Refund due but no paid

I app**** online for a mobile contract that included a device. I cancelled the contract, but the device was still delivered. I returned the device unopened. To my shock, i later found that i was billed for the contract. I logged several complaints and after quite a few attempts, it was found that i was entitled to a refund. But now i am given a run about. Telkom does not want to refund me.