Negligent customer service

During August I received an sms stating that my application for an additional contract has been submitted to vetting and should call the MTN call centre if I didn't make the application. I called the MTN call centre because I didn't apply for another contract but they told they can't see any new application on my account. I called them again on 14 August and they told me the same thing. However they sent me an invoice with a number I didn't know and also went on to debit me an amount higher than what I should be paying. I sent them documents they requested for investigation and after they determined that it wasn't me who app**** for the new contract they started ignoring me when I mentioned being credited the cost that was debited relating to the cell number I didn't know. The customer care mailbox operator Kgoitsimang Tsotetis started ignoring my mails when I raised this matter. It is clear that MTN is prepared to ignore this matter until I give up and leave it to rest. I am still surprised that how can MTN assure me that there is no application that was made while they are busy processing one. This shows that with MTN, money comes first and the customer after.