MTN is the worse service provider on earth!!

MTN has messed up my account on numerous occasions. In fact, they still owe me money from 4 years ago. I went on and on about it sending emails, calling them it just never worked! Then, later, I upgraded one of my contracts and was charged double for the transfer, I queried that numerous times as well, this was abut three years ago, but alas, no credit form MTN yet. THEN, I upgraded my contract, the guy told me I was going to get 500mb of data free every month, it's been almost a year and I have not received even one mb for free! I queried this months ago, but again, another matter left unresolved. I received my account this month and my account went from its normal amount of R550 to R1 908!!! They told me that I was charged for data as I didn't have any data left, but I checked my itemised billing and know for a fact I called to load data on the 22nd of Sep but it was never loaded! I give up on MTN!!!! I have three contracts with them and can simply not wait to end all three of them!!!