Appalling service!!!!

I called MTN to cancel my contract end of July. I received an SMS stating my contract is canceled and that my last payment would be on 06/08. I still got billed for September though. Today I receive a call from a salesperson, telling me that I couldn't cancel before but I can cancel now and he will help me. When I asked him why is this so confusing and why my previous cancelation wasn't valid he couldn't answer me. He then says he is canceling it now for me and then I received another SMS stating that my contract is canceled and the last payment is due on 09/12???? How is this possible as my contract was finished with the 24 months in July already. MTN STOP BILLIBNG ME!!!! Cancel means stop, I don't want your business!!!!! After emails have been sent, calling, and staying on lines for 30 minutes and still no one answered, I am left with giving you this review as nothing else seems to make you want to improve your service. This is honestly the poorest service provision I have seen in my life. You should consider working as a public entity for the government, they do things the same way!!!