Pathetic procedures

I upgraded my contract on Sunday 07/06/2015 from a voice package to a 1 GB data package. I received a message yesterday saying that my credit limit has been exceeded and the account has now been suspended. The tablet is of no use at all now. I went into the MTN SP branch (not the one I concluded the contract at) to query the problem I was then explained that there was no limit set on this contract and the default credit allowed has been exceeded. My anger stems from the fact that I was under the impression that you only get the 1gb data a month and thereafter you would need to reload data. the fact that this was not the case was not explained by the consultant at the time. My frustration and annoyance stems from the fact that I can only officially log a query on the 20th when the bill closes. THIS IS COMPLETE ****ING ********!!! The tablet is now of no use unless I pay in to reduce the credit or increase the limit, but the ****tard who sold me the damn contract is not held liable although he did not clear this to me or even discuss the payment/billing process with me AT ALL!! MTN ARE BUNCH OF ****ING *******!!! I DON\T KNOW WHY I STILL BOTHER WITH YOU!!!"