Breach of Contract!

I upgraded on Friday on 05/06 at the MTNSP Pavilion, was told that because i was taking a package that was R79 more I have to wait for MTN to do credit limit vetting of some sort. Just before leaving the store i received an sms stating that the upgrade was successful. So the store clerk processed the upgrade and gave me the new phone. Everything worked until Saturday morning when I couldnt make any calls or anything to my horror I find out that My account has been suspended! I am now stuck with a new phone that I can not use and the R600 worth of airtime is sitting unused & on the 10th this will be forfeited. I went to nearest store for help they could only send an email & said it takes between 2-24hrs. I then called the call centre logged a call *** who said that if he logged another call it would take longer. Then today i logged another call *** was told he was sending another request & I should restart which i did and that still didnt work. I am SO FED UP! I REGRET not porting to another SP! MTN you have wronged me once again! after being a LOYAL customer for more than 10 years and never defaulted on a payment! I would like to be compensated for this!