Why am I being over charged?

Good day,<br> <br> I joined Virgin Active in July. Elizabeth had told me that they are running a special where joining fee was R700 for Vitality clients after which the installment will be R120 per month. Furthermore she said the 1st month was free. I told her that I don't have that kind of money and I will return at the end of the month when I have money. She then said that there was another option where I do not have to pay joining fee if I don't activate vitality then I pay R595 the first time after which she will activate vitality so that going forward I only pay R120. I asked her if I will need to pay joining fee when she moves me across to vitality and with a straight face she said NO. A week later I was charged R595 but the first moth was supposed to be free. After querying it it was then reversed and I was only charged R595 end on Aug. I wasurprised when I was charged R595 again end of Sep as Elizabeth had said it will be R120. I called her, went to the gym in person, left messages for her to no avail. Until I eventually got hold of her and she admitted that it was her mistake for not explaining to me thoroughly. I want this contract cancelled. I do not do business like this at all