Incorrect amount debited month after month!!

In March / April I had subscribed to a new contract with Cell C, R359pm for 50gig of data. Since then Cell C has been deducting R457pm from my account, I have been to the Cell C shop in Lephalale Mall to no avail. First they told me that the extra amount was to block me from exceeding my limit, I then told them I did not agree to this and they should cancel it. The incorrect amount was debited again and I went back to Cell C, according to them they did send in a request that the correct amount should be deducted and that they furthermore can not assist me with this issue.

I have send an email to ***, it bounced back, I then called the customer service on the 6 of August, the lady Fikile Zulu told me to email her on *** and I still haven't received feedback, Today I called the customer service again, was asked to answer security questions and then failed, the lady then proceeded in telling me that I should read my contract, a contract which I have never received.

This is unacceptable as I never agreed to the R457 pm and would like to be refunded for all the excess amounts charged to me and for Cell C to rectify the amount that needs to be deducted for the remainder of the contract.

Very poor and unacceptable service on Cell C's part.