Disputed credit limit

Currently I cannot use any data as apparently I have reached my credit limit. No credit limit was communicated to me, as the current limit differs from the one from before. One of my contract lines were suspended before it was even communicated it will be suspended. Secondly trying to get a hold of credit control is a nightmare as do not answer their phones, as well as customer care tell me every time to phone them, and do not even attempt to put me through to the manager, They keep on telling me they cannot make outside calls. I even requested that one of the customer care managers contact me, but to no avail. My account is paid every month, and that is what really ticks me off. I have been with MTN since 1996, and it is the second time I experience this absolutely appalling service. MTN is quick on the trigger to disconnect services, but if they do something wrong like bringing the whole network down, it is only a \Oops