MTN has the worst Customer Service in the World!

MTN has the worst Customer Service I have ever seen!! I have been phoning and sending e-mail for a month now. If you phone the 135 number, you get put on hold for such long periods of time that you eventually put the phone down or get cut off. I am desperately trying to cancel a contract. Number is ***. I have so many reference numbers and return e-mails where they promise they are looking into it and will contact me BUT after a month still nothing and my contract is still not cancelled.!! This is ridiculous. My son's phone gets disconnected EVERY month for short paying a small amount (sometimes a R100 or so) but our monthly payments to MTN is around R2,500 per month. I have had my contracts for many many years with MTN but wish I can cancel all 6 TODAY as I honestly can't take their *********** service any longer.