How to mess up a contract

In November last year I went to upgrade my one line. Specifically asking to stay on the same contract that I was. R200 top up. (all my other lines are also TOP UP'S. And adding 1 GIG data on this package as well. If I just knew then what nightmare was lying ahead. In April I received a Bill of R 5 500 just for Data used. On the 21st April I phoned the branch to find out was going on. They informed me I was on a anytime 200 contract. I had a 12 minute conversation with the person. He promised me he will lock q complaint. A week later I went to the store to get feedback and nothing has been done. The manager only then reported it on the 28th. My contract was also changed back to Top up. Branch says it is head office and head office say it the branch. I also phone HO a number of times. Nobody coming back<br> 1. I still want to know why my contract was changed( Well the lady who did it is not working there anymore.<br> 2. Why was my 1 gig data taken off when the migration has taken place. (MTN give extra so we look at 2 GIG<br> 3. What happened to all the data that was on the line before the migration took place, data that was bought on the top up out of our own money. The purpose of a TOP UP