Swim-swap issue

Please assist me. I took a contract for my sister when she was still at school, the contract lapsed and converted to prepaid. sometimes last year she battled with the sim card not reading and when she called she was advised to get a new SIM Card, because the number RICA details are on my name she asked me to do it. When I did in January she couldn't remember the last 3 numbers she dialed or airtime on her phone . Last week I then went to Cell C store at Carlton Centre and Spoke to Mmabatho who told me that even though the number is showing active and re-allocated on the system there's nothing they can do about it as it's more than 6 months. can someone assist from IT, I have a contract with Cell C and both of the numbers are on my profile ********** 883