Account locked after upgrading

I upgraded my contract from a Flexi 185(R109pm) to a 5GB data contract (R99pm). The day after I upgraded my contract I received an sms confirming the upgrade and another sms stating "credit limit exceeded". I called trying to find out what is happening and was told that once the debit order goes off the lock will go away,as the credit limit got set to R99 and the "outstanding" amount was R109(I upgraded on 30 Aug). Now it's the 5 of September and I still can't use my data or make calls, and everytime I call the call gets dropped. When I finally get through I am told that I need to pay a fee to activate the account? Surely this can't be right? I mean I upgraded my contract,got soft locked due to a system error and now need to pay?