I bought a ticket on trainline and used rail card (train going to Edinburgh from Manchester ) my ticket was checked while in the train and was asked to produce a rail card . I showed the conductor . Then he said I’m not supposed to use the rail card for the journey , said it only works for London trip or south east which I didn’t know . I explained to him I didn’t know and he said it’s my responsibility to know where to use it . I just go on trainline and buy the tickets , my railcard is already on it . I didn’t know I was supposed to deactivate . He then said I will have to pay about £150. I told him I’m a student and don’t have up to that with me and it’s just an honest mistake that is there any way I can get it reduced . I didn’t know , it’s my first time hearing that as I’ve been using it before . He then asked I show him my history which I did , then he start snapping my tail card and said he’s going to forward the case to his office . I recover a letter today from transpennine express saying I should respond by making comment about the incident . Please what should I do and am I in trouble ?