OVERCHARGED AND BEING HARASSED

last year i had one of my contracts had ended and i asked vodacom to cancel in January which they didnt , i only realized this when i tried to do an upgrade on my other contract. i called in and was advised that the consultant made a mistake and the cancellation was only done in February which means i had now been charged in january , i was advised that this will be cancelled and a credit will be issued for the last month. a year later this crediot has not been done and has grown cause of the intrest. the worst part is that instead of vodacom calling me they have called my sister whom they hjave since shared all details of my account with her, my details have not been proptected as per Popia , the consultant that called her was Pienaar who makes threats about the device being collected by Vodacom , the frustrating part is that i make payments monthly towards my account , im being harassed for an error that was caused by Vodacom them selves. furthermore after they contacted my sister somehow they manage to go and change her number on her Experian to a number that belongs to me, how is that possible? how does Vodacom access another persons details that does not have a contract with them. my sister is being called daily and no one is calling me. on the 4th Feb 2025 i called in and spoke to Lunga Kheswa who advised that a credit will be done in 7 days , i then requested a call back from the manager as i need my matter to be escalated, i have not received any calls from her , even today i have called them 2 times. however they still manage to call and harass my sister so mayny times and harass her for a product which is not in her name. even with the notes on the account stating the matter is being investigated. this has become so tyring as i have been dealing with issue from last year. can someone please have this matter sorted out now.