Virgin Active Rob their clients when canceling

Try canceling the membership with virgin active you will see true colors. In April was called by a lady called Zodwa and inform her to cancel my membership and she can calculate the amount I owe them she advised I would be pay R515 and asked when should they deduct it I then informed her end of April and she advise she will be sending a once off debt order mandate which I need to accept. Once the payment goes successful the membership will be canceled that was the agreement. May came I received a call I was advised I owe R420 by a consultant I then explained to her that can not be as I canceled the membership she then advised the contract was never canceled. I have been sending them emails receiving calls of different amounts I need to pay. Each time I get a call it's a different amount Monday was told to pay R157, yesterday was told to pay R575 today I receive a email that they agree I paid the R515 but I needed to pay another R515 which will make it R1013. This does not make sense they rob people. Firstly my agreed contract with the was for them to deduct R340 every month but last year December they then started deducting R420 which I don't know who agreed with that as I don't recall signing a R420 contract, but I never query it. This is too much firstly they can pay back the extra amount they deducted without my knowledge in December cause they actually owe me not the other way around. How did R340 ended up becoming R1013 that I need to pay now.