over debited

im currently paying R239 FOR JULY YOU DECIDED TO DEBIT R489 from my account i immediately called MTN and was told the quiry will be locked and accounts person will contact me , 3 weeks after i called again and spoken to Lulama who told me i will be contacted about the qury and i told her if nobody is calling me ii will reverse the debit which i did today 2015-09-04 you have guts to send me messages and tell me my account is overdue this is **** service i have never requested MTN to load 2 gig on my account and i have nver seen it , i called and spoke to Nolubabalwa who told me there is no quity loaded on my name i have been wasting my time calling trying to resolve this she told me and gave a qury number *** which doesnt help me with anything because i have spend money calling the incomepent agents didnt bother to load my quiry , i need someone to give me settlement figure sos i can close this stupid account and move somewhere else where i will be treated better