POOR CUSTOMER SERVICE

I have been waiting for MTN supervisor by the name of Ndumiso from the "call centre" to call me as he promised, MTN customer service is so poor that even a supervisor can not keep a simple promise ,it has been more than a year that I have been struggling to get my invoices with MTN every time I get charged but I don't even get an invoice so I don't know if MTN is over charging me since they refusing my right . it's easy for MTN to debit my account every month with no fail but difficult to send me an invoice of what I have been charged for. I now believe that the call centre agent ain't trained to handle queries cause clearly no one can resolve my problem,they keep on telling me it's been resolved yet i still don't receive my invoices a year/months later.MTN services is so pathetic training is needed from the call centre agent to the supervisors what is Bhoza about poor service? MTN 'stop calling yourself Bhoza network you are not even close to it ,sort you poor customer service, I read an articles where clients were complaining about MTN extra charges on their existing contract ,maybe that's the reason I don't receive my invoices cause you hidding the extra charges on my contract. I'm tired of calling your customer care cause clearly no one knows what they are doing!!!!!!! I need answers I'm tired of waiting and hoping..