Rmcs is a ****

Please I would like rmcs to remove my number from their contract I never requested any contract with them I just bought a sim from shoprite and automatically turned to a contract I don't even understand how rmcs got involve in this please remove my number from your contract I want it to be a prepaid I don't need your free airtime that comes with an expensive tariff per minute and my number keep on giving me not registered to network message and I cannot get any help from cellc because of this rmcs