Unauthorised Debit Order Amount

I have been a tracker client for years and I received a call from a tracker agent telling me that my contract is expiring and I must renew, to which I agreed to a month to month contract and I specifically stated that Im a pensioner and as long as the premium remains the same or is less than R199. The agent tried to sell me all these other extras to which I declined. Much to my surprise yesterday, numerous amounts totalling up to R500 odd amount was debited to which I did not authorise. Can someone please contact me and reinstate a month to month contract that is affordable to me and exlude all these extras that I didnt agree to?