VERY FRUSTARATED MTN clt ...

MTN... Another sms saying my account is in arrears ??? I have send prove of payment x3 in 1 month just to try and proof that my account is up to date and every time they reconnect my line but no fail in a week I get another sms with a different amount saying my account is outstanding and my service will be suspended ??? I am feeling hopeless MTN is just the worst service provider ever... someone is not updating payments something I am sure is still outstanding on my account ! can any competent person update my account so my line can stay on. I AM VERY FRUSTRATED!!! I don't even know how much to pay this month as I received my statement with 1 amount and sms with a different amount.