Still billing me for a cancelled contract

I had a 12 month Stellenbosch University student internet bundle contract at R99 with Telkom which came to an end on 30 June 2015. <br> <br> I cancelled the contract on 31 July 2015 after receiving a R800 bill from Telkom. <br> <br> After numerous calls to the Telkom call center and visits to the Stellenbosch and Tygervalley branches, the contract has still not been cancelled. <br> <br> All I have to show for trying to cancel the contract is a bunch of reference numbers and 3 bills.