Number handed to legal but no outstanding amount

My one number was cut-off. When we enquired about it the call centre agent told me that this has been handed over to their legal department. I asked what the outstanding amount is and wanted to make payment but the call centre agent send an email to the legal department to call me back. This happened on Tuesday 12 September 2017 and the agent assured me they will call me back in next 2 hours. I still waiting for this call. However I did manage to speak to somebody in the legal department. According to them the number is completely cut-off and that there are no outstanding amount. They cannot provide any plausible reason why this happened.

How can MTN do this and not have any reason for their actions.

MTN service are in general below standard and disappointing. I will currently not continue any further contract phones with them.

This is completely unacceptable MTN!