Near impossible to close account

I signed up with skyfi end of Feb 2017 while we were staying in Johannesburg. I had the 10mb package for 739.86 per month. By end of September 2017 we had to relocate to a small town in Mpumalanga. Naturally I had to cancel my internet with them. I phoned them to ask what the procedure is to cancel and the lady advised me that I have to send an email to ********** and they would contact me. I did do this and nobody ever contacted me. Next best thing I receive a statement stating that I must pay almost 7000. Shocked, I immediately started phoning them with no success. Eventually I got through to somebody and he advised me that everyone from the accounts department had gone home, but they will contact me first thing in the morning. Nobody contacted me. I have been unable to have contact since that time till January. Then in January i received an email stating I need to pay my account. I immediately responded to the email stating that I have cancelled in September already but have received no contact. I also attached proof of my email I sent. The lady then rep**** and said that they will process it. A week or so later I just got the same email stating I need to settle my account, which was now 10000 already. Since then I have constantly been trying to communicate with them to explain to me how it is that amount, only to receive a response saying I must look at my AR invoice. I am not an idiot, I can see the invoice states that amount, I want to know why the invoice has that amount but nobody seems to be competent enough to help me????? Yesterday I phoned them again and I spoke to a lady and explained the whole story and she said she will get someone from accounts to contact me immediately. Not to my surprise, nobody has contacted me again, and they just keep adding monthly subscription fee to the account. This is probably the worst operational process I have ever witnessed and I promise you if they do not assist me I will spread the word of this pathetic operation on social media to all my known contacts to protect them from falling in this same hole that I am now. I am past furious at this stage and only want to settle my account and be rid of this isp forever, but I am not paying 10000 as that is a ridiculous amount.

Please if anybody has had this experience or know somebody that I can contact who can actually help me, I would greatly appreciate any help.