Cell C
They advertise 99c per minute than charge 5x more

I cancelled my contract with Cell C via Autopage and transferred to prepaid for the Cell C 99 cents per minute rate in January 2013.

I became suspicious that I was being charged considerably more than 99 cents per minute and started to investigate. Examples of discrepancies found:
Call 20 Aug 2013 to 082 331 3102, duration 3, 20, charge R9, 55
25 July 2013, call 085 766 4212: Duration 53 seconds, amount billed R5, 09
25 July 2013, call 076 147 9456: Duration 1:17, amount billed R3, 76
30 July 2012, call 082 325 0055: Duration 1:29, amount billed R4, 28
14 August 2013, call 076 091 8096: Duration 1:07, amount billed R3, 23
18 August 2013, call 083 651 4436: Duration 1:42, amount billed R2, 24

I enquired at the local Cell C branch, and was told that I was being billed at rates from my cancelled Autopage contract. They could not tell me why this was the case and why the rate had not been adjusted. They changed the billing rate to 99 cents per minute from the date that I visited them, but were unable to do anything about the backdated incorrect billing.

Solution description:
I would like the overcharged balance on all calls since January 2013 refunded via a credit on my account.