Incorrect Telkom Bill after service re-location

I relocated residence within the same suburb on the17th August 2015, Telkom issued me with a new telephone number. they continuously billed me on the old number which I requested to be cancelled after being issued with a new number and then I asked for an account. they send me an account back billing me to May 2015. my old number was fully settled I am disputing the bill and called the billing department who said that Telkom will called me the next day. the account was due today and refuse to pay the full amount.They have not credited my account for all amounts paid for may to date. They have sent me a bill of R2387.45 yet on a monthly basis would payR400 and settle each bill. To date this has not been resolved after numerous calls to Telkom Billing.