There is no phone number to call.

Yesterday a new version of app. This version has a bug so the first thing to do is to reinstall the app and then try to connect your pass again.

You don't need the pass in the app to make reservations as the advice from the experienced travellers in the community is to use other ways to make reservations than the Interrail/Eurail website. You can look at the guide in the link:

https://community.eurail.com/train-connections-reservations-47/how-to-get-reservations-105

If you, after having looked at the guide, have questions about how to make specific reservation, please create a new topic with your travel details (departure date, time and route) and you will get advice.

Thank you but this has already been done 5 times with no solution. Does anyone know how to cancel the purchase?

Here is information about how to get a refund.

https://www.eurail.com/en/eurail-passes/ordering-info/refund-exchange-policy