Telkom Mobile 2nd Contract Error

In Nov 2015 I app**** to upgrade my cell phone contract with Telkom Mobile. In Jan 2016 the device finally arrived but I later discovered that instead of upgrading the existing contract they had added a new contract with a new number. I immediately returned to the Pavilion Store and Gwen assured me that she would rectify this by cancelling the second contract and upgrading the old. A week later I realised nothing had changed and returned to the store. Siphume assisted me and said the Gwen had messed up and she would rectify it. I gave her the second Sim Card and she destroyed it. A week later nothing had changed and I went back to confront her. She apologised and performed the upgrade in store but said the second contract cancellation would be escalated by her manager Vernon Stewart. Vernon ignored my emails. At the end of Jan, Feb & March I was billed for 2 contracts. I've tried the Call Centre on numerous occasions but all I get is a different excuse each time and more promises that this second contract will be cancelled - but nothing has changed. Please cancel & refund me asap before I switch networks.