seeitclickit I took out facebook advert with them paid over 300 euro. ad never existed and I cant cancel my contact as it has to been in formal written letter. I have already written twice but wont acknowledge rec manchester, Other

I got a cold call from a guy in manchester, i am from ireland, askinhg me to take out a facebook advert which would transform my business. I was charged over 180 euro to start with. I was promised a dedicated account manager to set up ad and preview it etc online. Never got a call or e mail. kept e mailing them until they replied with an email of what add would appear like. It had wrong name and phone number, now my subscription was well on its way at this stage and i had to wait until another proof of advert was done. a one line ad with a spanner on it, i could of done it myself...anyway I tried cancelling contract by letter twice but they did not recieve letters!!! I have been charged over 300 euro for a non existent ad. I have tried cancelling cred card but they say they will still be able to charge the acc !!!!!!?????????. They have told me they will try to back charge but that I wont recieve the first charge back. How can this be legal?