Vodacom contract cancellation

I have been a client of Vodacom for many year but due to me relocating to Saudi Arabia, I cancelled my contract at the end of August 2017. At first Vodacom deducted a monthly fee from me still at the end of August after already paying the cancellation fee. I contacted a Vodacom cancellation consultant to find out way & was told that due to me cancelling on August the 30th I was still liable for the fee but as of the next month I will not be deducted which was exactly the cast. No more fees were deducted until a few months ago & that is were our problem starts.

I paid the full cancellation fee, I emailed the proof of payment & cancellation info to the address provided on the document: **********

Now I have received letter regarding outstanding fees & they deactivated the sim card (which I have not been using since I left SA but stated that I would like to keep the number for when I am in South Africa) When I tried to call +27 82 1958 from Saudi only the machine answers and I am on hold forever. Plus now I can not call due to them cutting the mobile line.

What exactly should one do to insure that other people do the job that they are getting a salary for? This is so unacceptable & i seem to not be the only one with this exact issue.