BUD - FRA is still in their itinerary.

When they called to cancel VIE - BUD they were told to expect an email with the amount of the refund and I can see the “refund receipts” when I get into their reservation. They just say $0 refund.

Would the complete ticket rules be attached to their email confirmation from when the original booking?

If not eligible for a refund to the original form of payment, should they not be eligible for a future flight credit for the unused portion of the ticket?