Desperate MTN client!

MTN customer service is absolutely useless. I have had a billing error on my account since December 2018 and every month I call their 135 number and spend about an hour on the phone, I get given a reference number and an apology but nothing gets rectified or reversed! Every month my cell phone gets cut off with an SMS saying I ow them R7000 which I don’t. They have billed me for 2 cell numbers and I only have one! (And that’s only one of their errors!) They are unable to fix their mistakes and clients have no ability to escalate the problem. If something goes wrong with your MTN account you are stuck. I can’t wait for my contract to end so I can change to Vodacom of Cell C! I have wasted hours of my life on this. The final straw is that I am currently overseas and my cell phone is about to be cut off again and you can’t call 135 from abroad! Grrrrrr!