I bought a ticket from a rural station to a station that takes Oyster. I got off the train, swiped my oyster and continued on my journey to Liverpool Street. At Liverpool St I couldn't get through at the barrier. I went up to the guards at the barrier and said that there must be a problem with my Oyster as I couldn't get through. They told me to wait for an inspector. The inspector checked my Oyster and said that I hadn't swiped in at the station. I showed her the train ticket and explained what i had done. She said that she was going to charge me a Penalty Fare. I said that as she could see from my Oyster, I had swiped out at this station and done the same thing on the way back. She said it didn't matter and she would charge me a penalty fare. I said that I wasn't willing to pay a penalty fare but would pay for the remainder of my journey in full and gave her the money. She said that she wouldn't take anything but the full fare and penalty fare. I paid for the ticket but didn't want to pay for the penalty fare saying that I wasn't demonstrating fare evasion, had offered to pay for my ticket there and then (I approached her with the cash in hand) and didn't think it was reasonable to charge me a penalty. She began to make a fuss and said I could be prosecuted then demanded my name and address for the penalty fare. I gave her the wrong address as i didn't feel that I had to pay it. She called someone to verify the address and said it was wrong and that I was now going to be taken to court. Then asked me for a statement. I gave the statement and signed it and gave her the correct address. She said that I was now going to be prosecuted for fare evasion. I said that I had offered to pay the fare and handed her the money. She gave me back the money I had given her for the fare. I have no idea what to do as I don't want a criminal record. I could do with some advice on this please.