Wrongful credit card charges

On 19 February 2015 I signed to join Extreme Health & Fitness with an explicit agreement that I will pay the subscription on a monthly basis. I discovered to my horror that the full payment for three years was deducted from my bank account. I went to the gym on 24 February & requested a reversal of the charges & cancellation of my contract. I informed them that Vincent had willfully done the opposite to what I asked for and even altered the contract after I signed. They keep promising to resolve my matter but have failed to do so, despite numerous telephone calls and visits to the gym. In each instance I was told the same thing: that the gym had new owners who were aware of the problems regarding wrongful charges