Telkom is charging me for their employee' mistake

I have an issue with Telkom, the captured my debit date wrong,sales person provided proof they logged a case ***6 is not yet actioned now they are expecting me to pay their employee' s mistake, they changed me extra R200 this month, please help me is telkom now a **** do they rob people, I feel ****** by signing their contract.please help I cannot proceed paying telkom' s employee's mistake