VODACOM - *****??????

I just found out that my combined contract no that is supposed to be blocked is still in use????? How can that happen?? that no is k\linked to a contract how can someone else be using this ?????? I phoned the *** and a lady answered. That is why I can’t understand that my account is over R19 000.

I need answers or I will most definitely take this further. That combined contract with 2 no's are supposed to be BLOCKED, how can Vodacom just give a number to someone else?????? and where did that lade get the sim card????