telkom ******* are able to do a sim swop on your account without your knowledge

Not happy about Telkom, ******* managed to do a sim swop on my sim card and increase my limit on the account transfer airtime and spend up to the max amount, even though the sim card at the time was not in use, i logged a querry and got poor advise from the store, Telkom in Newcastle Mall. now they have max my bill after 10 years with Telkom and no one can assist nor help in store or at the call centre. even though they can all see the ******* activity on the Sim card.