Basic-Fit complaint: charginging double and changinging my contract without my knowledge

I have a contract for 1-time payment for one year of 239.88 which is 19.99 a month and 4 weeks free. But instead, I saw that they only charge me 19.99 In fact the person that work there had to help me and he chose one time payment. In either case, I have a contract. They charged me double in November 199.99 x 2 and January 29.99 twice and then 29.99 each month they owe me 109.98€ charged on my credit card and every time I have complained about it I have been ignored by the people who work at Basic Fit and Also my emails by basic fit and I wrote a letter neither time have they correct the overcharge and each month they charge. My husband has contacted the bank to stop them but we want our money back. But they tried to say we don’t have 19.99 anymore which is not my problem. But I see they do have 19.99 a month. I had to change the number on my card because someone from the club that works there I believe was letting their friends in when I was not there.I can send the copy from the bank of all the charges with the dates on Tuesday