Unauthorized money taken

So I have app**** for a contract with Telkom in July, as the agent told me repeatedly that I will only be billed for the one contract. Low and behold Telkom charged me for both contracts. I cancelled the next day, have never used the services, asked them repeatedly to pick up their stupid device, but up until today they are taking money from my account, which I am reversing monthly. Telkom, your stupid *********** services have ruined my credit and its on my report as it states I owe you money, WHICH I DONT! Sort this **** out, I have logged 13 calls to this pathetic company, that always seem to have a issue with their client. Their call center agent **** flat in my face, and I will never trust this company ever again! Do not take out a contract with them, I will again instruct my bank this month to reverse this debit order, as its unauthorized, as they are also refusing to cancell this. My mind is made up to take legal action for damaging my credet. They need to sort out this hole of a mess, that they are creating! Such a bunch of *****!