I have paid and they still suspend my account

My name is Thembisile buthelezi I hve been a loyal Mtn customer for a long time now, in December I made a payment of R200 then followed it up with R650! On the same day Via EFT I hve had them as a beneficiary for more than 3years now n never had problems.... They say they haven't recieved the R200 but they recieved the R650 so they suspended my account. I went to the bank got bank statements that prove the payment went through ,and the requested I send them the statement I have but they still have not cleared and they are threatening me to cut my line again . I am sick and tired of running around and the poooooor and rude service I get from these people I want my account cleared now. MTN not tomorrow now