I used Save A Train when I couldn't get a transaction to complete on SNCF. I always go to the country specific site first. The French train site has always been pretty surly about accepting U.S. payments. Save a Train was then recommended by a frequent forum contributor which is why I'm back asking for help with the transaction. I ended up with a voucher because of a cancelled trip due to COVID. I have already contacted them via their "contact us" link.
@Dutch, It is probably different for someone in Europe to purchase train tickets from some of these country specific websites. SNCF/OUI is notorious for not accepting U.S. credit cards. RENFRE is now problematic as well. There are many reasons people resort to the 3rd party sellers. I agree that it is more difficult when a problem arises to have a 3rd party involved. However, I purchased two sets of tickets for a 2021 trip that was cancelled. SNCF wouldn't work. I purchased the set on Save a Train and the other set on Trainline. When it was time for a refund for the cancelled trip, both Trainline and SNCF were IMPOSSIBLE to deal with. They kept bouncing me back to the other, and I never got the voucher I deserved. At least Save A Train fairly conveniently provided a voucher. Now, of course, it would be nice to use the voucher. . .
@Nigel, I'm trying to go through my search history to find out who recommended Save a Train thinking they might have some insight on how to reach them. My recollection is that it was you or Toccard? Ring a bell with you?
Save a train issued the voucher for a cancelled trip during COVID, trip was Paris to Bordeaux.