Worst service

I've been a customer at Cell C for almost 8 years and never had any problems until now. We just recieved messages from HP attournies telling us to settle our account. We phoned Cell C and we were told by the agents that we have nothing outstanding and are elegable for an upgrade. When we are put through to the upgrades department we are told that we are in arreers. We then wanted to know how this is possable since we have a debit order with Cell C and our statements balance is zero. We are put from one department to the next and no one can tell us where the problem is. According to our statements we are fully paid up. We then pulled a years statement and discovered that Cell C incorectly billed us over 2 months. No problem, we paid the money, but still a month later we still recieve messages that we need to pay our account. We now have a bad credit rating for Cell C mistake. These big companies are messing with their clients. We have mailed our statements to the attournies, all they tell us that they have not recieved it. How can Cell C and their attournies not communicate with one another, how can Cell C now send us statements that tell us they now ow us money and at the same time their attournies tells us we ow them money. It is useless to even try to speak to either party, and so I have decided to approach my attourny. There is no client service from Cell C!