Membership entrapment. I enrolled with a internet based service on a 12 month contract (February 2011 - February 2012) and initially paid my membership monthly with a credit card. In September my credit card was stolen and subsequently blocked and the company contacted me and advised that I now had to pay the remaining membership fee in total via bank transfer. I asked to terminate my membership but was told I had to remain a member and pay the fee until February 2012. I reluctantly paid and emailed back stating that I wanted to cancel my membership at the end of the contracted period. The company told me email was not sufficient and told me I had to send a letter. I did but kept no proof of postage. This year, in February they contacted me demanding I pay a further 12 month membership fee until February 2013. They claimed they never received my cancellation letter. So I sent them another one. This they received but said it was too late and continued to insist on payment of the unwanted 12 month membership. After several complaint emails, they are still insisting I am forced to have the 12 month membership but are offering me a 30% discount. I want to know if they can legally do this and if it really is so that I have no option but to pay?? I thought email would be sufficient written cancellation? What does the law state?

Already Tried:
Number of e-mail complaints and letter to the managing director.