10 year Telkom mobile client very disappointed !!!!

I have been on Telkom mobile contract since 2014, just last month I decided to switch over to prepaid from post paid, the process was followed to the letter, since Friday last week when the change should have taken effect my SIM got locked. I called the call centre and they sent me to a store where they made the same call to the customer care to assist, they apparently have an indicator for ***** which is convenient for them considering they will not be getting post payments from me for the next 10 years, I am highly disappointed and angry because my SIM and number I've had for 10 years is blocked and they will only be able to investigate after 72 hours, this is an inconvenience and very suspicious.