Bad service from Telkom Mobile and Nudebt Management

I took a 2 year phone contract on the 29 March 2014 with Telkom mobile which was a Samsung S4 and I would be paying R369/month. The month before the end of the contract sometime in Feb I contacted the call center to find out what steps would I have to take to officially close the account, the call center agent said that I would have to download a form on the internet and thereafter email it to her. I did exactly as she told me and expected that Telkom mobile would debit for the last time in March. The following month Telkom mobile debit from my account again. I called to find out why, they said I did not cancel the contract. I then explained to them what the call center agent said, they then said that the agent gave me wrong information and that I was supposed to go to a Telkom mobile store instead. From that moment on wards I started reversing the debit orders because I felt that they handled my case unfairly because the people working for Telkom mobile gave me wrong information. This continued until last year October and at that moment I decided to just pay the money (end of November 2017) that they say was outstanding because it would reflect badly on my credit. at this point my father was telling me that there is someone who is calling me regarding money that I owe but could not fully explain to me who and how. I ignored it because firstly they were not calling me and secondly I had settled my account. Fast forward to 03 March 2018 I notice a debit order of R247.67 from Nudebt telkom as the reference. I called Telkom mobile to find out why they were now debting from my account again, they response was that they are not aware of that debit order done and that I should call Nudebt Management. After many attempts to get through the debit order department they tell me that I owed them 8 hundred and something which is penalty and they standard amount that they charge including interest. I feel that this is not fair because this was not even communicated to me and had Telkom mobile done it's job in the first place I would not be going through this. So these people want to bleed me dry basically!!!!