Unauthorised Debit Orders

On Air is the worst company to deal with , I have a 24 month contract with them for R159 for a DSTV Explora , which I entered into in Sept/ Oct . Instead their are now taking three debit orders , of which two are unauthorised. And one of these amounts keeps increasing. Just today ( 30 Jan 2020 ) the debit orders are as follows R 159 , R 169 , and R 507 . I keep reversing and they just keeping debiting. Their consultants are also the worst and just have a don't care attitude. Multi-Choice please assist because this company is selling your product and then they take advantage by processing ******** debit orders once you agree to the DSTV Explora. This definitely unfair because this is my hard earned money and they causing havoc.