We have seen cases like this before. Please contact customer service to have it resolved. Do mention when your trip starts, so they can prioritise correctly.

In the meantime, you can book reservations elsewhere. If you specify which trains (origin, destination, date, departure time), then people can advise where best to book.

Thanks for the reply but seat reservations cannot be made as an error just keeps coming up due to the apostrophe and all others in the group are now booked to specific trains except me 

I repeat: if you let us know which trains (with details) you want to book, then we can suggest other ways to do it. The Interrail website is by far not the only place (and certainly not the cheapest) where you can book reservations, e.g. see this page and this thread.

It would also have been better to book the whole group together (so you would be seated together) but I guess it's too late for that now.

We were trying to book together but an error kept coming up and no one realised it was due to the apostrophe at the time so trying different ways the others eventually all got to book and only when one was left was it realised that it was because if the name 

Train is Friday July 8th 

7.24pm Paris Gare de Lyon France 

to 

9.26pm Lyon Part Dieu France 

In that case, just call SNCF to book. Press #85 for English, no booking fee, reservation is sent via e-mail.

If you have a coach and seat number of one of your friends, then you can give that to the operator to be booked near that seat.

By the way, I think you mean TGV 6643 at 7:30. Price should be 10€.