Unhappy Customer

I took a phone contract in Dec online, when I got the phone I was not happy with it so I cancelled the contract within 7 days after receiving the device. Telkom debited R8 918 on the 29th Feb for phone retention and I reversed that debit order, they debited again today 15th March R9 097 and I reversed it too. I have logged calls with Telkom concerning this, I have provided them with Reference numbers when I cancelled the contract and the courier way bill to prove that they collected the phone but still there's no solution to this.