PATHETIC TERRIBLE SERVICE

PATHETIC TERRIBLE SERVICE, I have been using my Mtn number for a couple of months and out of the Blue an error message popped on my phone saying Registration failed, upon several attempts to have this sorted i ended up going to an MTN Branch in South Gate and was advised that the sim card had expired i needed to do a sim swap, as i explained to the Consultant i need this number as they are certain things linked to this number, a sim swap was done and was advised that @ 8pm the number will be working to my surprise the number rang and another gentleman answered this number and i contacted MTN who advised me that the next day @ 1pm the sim swap will be finalized , after 2pm i call only to be told Supervisor did not release but my question is how come my number is being utilized by someone else furthermore how is it possible that 1 number is used by 2 individuals. SHOULD ANY DATA OR INFORMATION LEAKAGE MTN WILL BE HELD LIABLE FOR ANY DAMAGES. The ref i got from the last call is ***