Hi I was given a £20 penalty fare at dartford station for trying to use my oyster card. I used my oyster card at my local station Bexleyheath to get on a train to dartford as I got off at dartford and approached the barrier there was no oyster sign to put it on so I asked the staff at the barrier where I could pay to get through with my oyster, he replied I cannot use my oyster and he had to fine me. I told him that there was no information about oyster cards not being allowed at the train station ( I checked national rail and southeastern) I the asked if I could just buy a ticket to get throug the barrier he didn't say anything and just asked for my details. Can I be fined for using my oyster card at one station and trying to use it at the next station? I don't see how I can be fined as I had paid on my oyster to board the train at my local station and I had enough money to pay for a ticket to pass through. I was not planning in getting the train back as a friend of mine wad going to drive me home later. Should I pay the £20 or appeal or not pay at all?