Telkom - ignoring customers and *****ing their money

I took out a contract with Telkom through Mondo in June of this year. The device and SIM card was swiftly delivered to my house and of course they couldn't wait to start taking my money. Two days after receiving the device I finally got the sms to confirm that the contract was activated and I could start using it. This was for a data contract on a LTE device. The device would not work, though. I phoned Mondo and was referred to Telkom as they handle the technical aspects. Telkom kept telling me to switch it on and off, which, of course, did not work. They were even kind enough to email me a set-up guide, which did not help at all.This went on for a week. I would phone them EVERY DAY, sometimes two to three times a day. Several consultants checked for reception in my area and all of them assured me that I did have reception. Finally I spoke to a lady called Christine Michael, who appears to be the only one around there who knows how to do her job. She realised that even though I have Telkom 3G coverage in my area, there is no LTE coverage around here and thus the device would not work. She immediately submitted a cancellation with Mondo and arranged for the device and sim card to be picked up by courier which was done two days later. But come month end Telkom still deducted the debit order from my account. I phoned their call centre explaining the situation and that the contract was cancelled and the consultant explained to me that it takes 21 working days for the cancellation to be finalised in the system, I would receive a sms when it was done and get my money back. I accepted this and proceeded to wait for the sms. By the end of that month, they submitted yet another debit order for a service which I have never received from them. I phoned the Mondo call centre again, this time quite angry. The consultant assured me that the contract had been cancelled on their side and that if a debit order was still being deducted, the problem was on Telkom's side. So I phoned Telkom and of course the contract had not been cancelled. The consultant send me the relevant cancellation forms, which was the first time any one mentioned that I needed to fill out any forms. I filled them out and sent it back on 21 August 2017. Month end debit order was deducted again, which I understood this time as I now knew it took them 21 working days to process the cancellation. About half way into September I phoned Telkom again because I wanted to find out when I would get back all the money that has been deducted for a service I never received. The contract was still not cancelled. The consultant asked me to wait another week, I should receive a sms. I never did. At this time I fell sick and did not give much attention to the matter. But come month end and they deducted yet another debit order. On 10 October I phoned Telkom again. This time the consultant I spoke to asked me to forward the cancellation form to him directly which I did while we were still on the line and he assured me that he did receive it and would forward it to the relevant apartment and get back to me within two days. A week later I still haven't heard anything back. I emailed again on 24 Oct and was ignored. This seems to be a trend at Telkom - ignoring customers. This time I stated in my email that I would cancel the debit order at my bank, not realising that I couldn't as it was set up on Telkom's side. So I started reversing the payments made to them, hoping that I would actually hear from them and we can get this matter settled. But, of course, there is no use in trying to get their attention, they simply sent through another debit order taking all that money again plus some extra. I am now at my wit's end with this company and this matter. I really just want to be rid of them and never in my life hear from them again. How do I get rid of them? And is there any possibility of getting back the money they are *****ing from me?