Impossible to cancel MTN contract

As U never have any signal at my home during loadshedding, I decided to camcel my contract. I went to the MTN store, waited for an hour for them to call 135 to get the early cancellation amount. I paid it and called 135 the mext day to request cancellation. I have phone them a million times since, it is now 10 days later and my contract is still not cancelled. I went into the store again, they said the only way is to call 135. Every time I call I either get cut off or a different story is spun. They cannot see the payment even if I give the receipt number as only the billing department can see it, or it takes 30 days to cancel. My contract expires in 40 days, why woyld they take my money for early cancellation if it is not immediate? I feel sorry for the MTN employees for having to defend such a failed company or have no job. What a disaster!