Please ask customer service and say it's urgent because you are currently travelling.

If you can prove residency outside of Europe, then maybe they can change your type of pass. I'm not sure if this is possible with a pass that you already started using.

Thanks for the suggestion

I already did that, but the automatic reply said that they would get back within 2 days.

Not sure when my request would be accepted…

Actually the mobile app wrongly registered a journey as inbound, and my outbound/inbound journeys were exhausted. I was really unaware of this. It wasn't even specified in the interrail/eurail difference page.

Do you have any other ideas of getting around this glitch? What do you think my best action at the moment should be?

Your best action is to contact customer service and you have already done that. They are the only ones who can make changes in the pass details, correct the number of travel days in/outbound journeys etc.

When you say "the mobile app wrongly registered a journey as inbound”, then what do you mean? What journey should not have been an inbound journey? Could you post the train details from My Trip?

The app took Berlin (Germany) to Bremen (Germany) on day 1 as inbound/outbound. We were supposed to go from Bremen (Germany) on day1 to reach Zurich (Switzerland) on day2.

We however changed to a faster train at Singen (Germany) on day2 to reach Zurich. This stopover at Singen which was also within Germany, was read in a inbound/outbound. I was completely unaware of this and towards the end of our journey I couldn't book a train to/through Germany, whereas my friends who had an Eurail pass could easily do so.

So the app did not registering something wrong as it’s written here, you simply did use both of your inbound / oubound travel days and the app registered this absolutely correct. 

You changed after midnight, which means you need an extra travel day.

Singen is in Germany, which also means you travelled in Germany and needed another inbound/outbound journey. So that was correct.

I now had a correspondence email from Eurail. They agreed to reimburse for the remaining travel days of my old interrail pass, provided I buy a new Eurail pass.

Hello Aditya! I have a similar situation to yours where I wrongly purchased the Interrail pass and now im stuck in Germany. Could you let me know how did the refund work (Did they give you the money or a coupon to buy the eurail pass?). Also, how much time did the response and the refund take?

The most important thing is to contact customer support:

https://eurail.zendesk.com/hc/en-001/requests/new

And tell them you are currently travelling.

It is highly unlikely that you will get an answer to that request as the majority of people only come here to get help with their issues and once an answer is given do not stick around to help anyone else.

As @rvdborgt said, you should contact customer support.