Virgin active Gateway debits without authorization

Kindly assist with an explanation for the debit of R1140 as my premiums are R280 and I was now on Month to month contract. I did not authorize any amount beyond my premiums to be deducted. At this stage I am disappointed with virgin active to be deducting so much without my concent. I would like to get my money back and cancel my month to month contract as I have not renewed or agreed to renew my contract. Then I got a call from one of their agents saying that they got an instruction from vitality to debit R 1140 from my account but can't explain why. They said that corporate will be in touch 2-3 days but still waiting.