You need a new reservation.

Thanks . I can’t cope with all these extra charges. 

You might get a sympathetic ticket officer at the window. 

You can also choose to travel with trains that don't require reservations. 

Thanks all. Yes, it would help if there was customer service 24/7 rather than limited hours/days and then no one answers the phone. It’s crazy that I cannot contact anyone. I have already started another travel day and I still haven’t boarded a train in 3 hours so far. I’m now at the station trying to get answers regarding changing the original reservation. It simply cannot be right I need to buy another reservation through no fault of mine. It’s a really bad customer service from the interail. Really shocking considering all the charges through reservations. There’s not a lot of choice without reservations unless you want to spend your entire holiday on a train.

You can't plan in Paris with to small time to change trains. In Eurostar trains at Cafe Metropol you get Metro Tickets for 2€. 

Also you would not get help by Interrail, because it is not their fault but yours with planing not enought time to change trains in Paris.

It is not the fault of Interrail that you didn’t leave enough time to get to the station.

Had you missed your booked TGV due to another delayed train then it would have been up to SNCF to accommodate you on a later train.

All of the itineries  interail suggested we’re around 50 mins transfer time Between montparnasse and gare lyon that I looked at. 
When at montparnasse from Rennes there were extremely long queues for the metro tickets and when it got to near the end of the queue, the machine broke down. I had to join another ticket machine queue. When I reached Chatlet, the connecting line was not operating. I then had to get a train to gare Lyon. That’s how I missed the train.

No fault of mine. I don’t live in Paris. I’m a tourist so I don’t know all the info. 
 

Still, after having paid for 1st class interail and with reservation charges on nearly every high speed train, the customer service is pretty non-existent. 
 

Anyway, in the end, after queuing for an hour at the SNCF office, I got a new reservation with no charge.

Its 5 hours later than originally planned but this totally due to interail’s complete lack of customer service.

I remember travelling on a round the world airline ticket nearly 15 years ago and had no problems whatever. You missed your flight or changed your mind, you simply got the next one. No hassle because you had already paid for it. 
 

Customer service is the key here. 

What exactly do you think Interrail could have done in this situation? They don’t run the trains, stations or metros, they have no control over what alternatives can be provided in situations such as this. It is entirely up to the train operators to assist you in these circumstances as obviously has been done here.

BTW if you had explained it was a connection between 2 rail services on a through itinerary you would have been advised to go directly to SNCF to get assistance for a missed connection. If you had said which train to where you may have gotten additional advice.

“ What exactly do you think Interrail could have done in this situation? “

Provide a customer service provision like any other company where I am a paying customer. 
People don’t stop travelling at 5pm or at the weekends. Eurail is where I made the seat reservations and they should be available to advise or transfer reservations that haven’t been used or at the very least, have options on the app to simply transfer a reservation not made to a later time or date. Ideally, like any other company, they should have customer advisors by phone who can deal with queries promptly and competently. 
 

If I have a problem with my travel money card I can phone customer services anytime day or night. If I have a problem with my flight I can speak to someone on the phone. If I have a problem with my bank, energy, provider, insurance, car hire, ferry operator etc etc etc I can contact and speak to someone on the phone to sort the matter. 
Why should Eurail be any different? 

The difference is that Eurail doesn't run any trains. Eurail has support if you have problems with your pass, but all issues related to trains and connections must be handled between the traveller and the railway company in question. 

“ The difference is that Eurail doesn't run any trains “ 

Its Eurail I book my reservations through. 
 

“ Eurail has support if you have problems with your pass, but all issues related to trains and connections must be handled between the traveller and the railway company in question. “ 

Limited support during office hours only during the week which is subject to them actually picking up the phone. 
So your telling me the train companies have a dedicated customer service for reservations made through Eurail ? Is that correct? Or do you mean I would have to go to an actual station, queue up for god knows how long and then speak to someone from the train company who knows very little of the reservations system, where, Eurail doesn’t give you an actual seat reservation but just a booking reference? 

It’s a shambles and the whole reservation scheme is an extortion racket. 

I would advise anyone to stay well away from the Interail pass and simply book your trains directly through the train operators. It will be much cheaper as some of the reservation prices are more expensive than the actual ticket for the journey itself. 
 

I would be amazed if there are many cases where buying a full price ticket with reservation is actually cheaper than using a global pass with a paid reservation. 

With a few exceptions most reservation fees are between free and 10 euros. 

The most expensive ones I am aware of are Eurostar, Thalys, Cross border trains such as Paris to Barcelona and SNCF TGV, and these are still cheaper than the normal retail price with reservation.

There is no doubt that once you take the “daily charge” on a flexible pass into account it may be cheaper to pay as you go if you are only doing local journeys or buying well in advance.