Billed 3 times my normal amount

I received an SMS yesterday (25/11/2015) to let me know that my account will be debited on the 30th Nov with the amount of R965!!! My contract is a top up one that is on a month to month basis and it is supposed to be R149. I tried calling the call center twice. The first time the agent said that she would escalate the issue and send me a reference number. This never happened. The second time I called the agent gave me a whole list of charges that are completely bogus. My contract ended in October and according to my contract I will pay a month to month fee for the data and airtime until I cancel the contract. If the original contract was R149 and I am not paying for the phone anymore, why am I now being billed R965??? This is the second time that I've been messed around with by Telkom and this is the reason that I did not renew my contract with them.