My friend and I live in the UK, and we did a university charity hitchhike (jailbreak) which lead us to France. The idea was to get as far away from campus within 36 hours without paying for transport, food or accommodation. While in France, we jumped on the TGV, without a ticket, with the aim of convincing the controller to let us travel for free. We had official documentation about the event and were wearing charity t shirts. Unfortunately we were unable to convince him and have been issued a fine of £150 each. We have yet to pay as instead we gave him our names and passport numbers. We are going to write a letter to SNCF explaining the situation to try and get our fines revoked, but if that fails, we were wondering what would happen if we just didn't pay?