Account Payed Still been suspended

Hi<br> <br> I paid MTN on the 31-05-2015 in order to get my account up-to-date. I when in to one of there stores to get my services reactivated and to give them proof of payment. All was good until today when I was suspended again. I have tried to call the call centre but as per usual there is no answer and you just get cut off. I have had enough of this. I have paid my account but just keep on getting cut off. This needs to get sorted out immediately as this is not on. PLEASE SORT THIS OUT ASAP