Phone locked without advising - account fully paid

I called on Thursday morning after receiving a message that there is unusually high data usage on my account. I checked online and it was in fact already standing over R19 000 - ps - this is the bill that is payable at the end of November..My account is fully up to date. Yunus logged a service call Ref: S3-9J91D-DMPC0. Shortly after this, my account was locked and I can no longer make any calls. I was not adivsed that this would happen. I called back and spoke to Phumi. She told me that there is nothing she could do, but that it would take 24 hours to be resolved. This morning at 09h45 I called back and spoke to Robin who advised me that it would be locked for potentially 14 days, and that there is nothing that can be done. Is this how you treat people who have been with you for more than 10 years? I have a bill of approximately R2000 per month. Obviously this must be some mistake? Can SOMEONE please take some responsibility and see what is going on, and perhaps give me some feedback?