Bad service

Poor service I’ve tried contacting them and going in store regarding my bill which I don’t understand. No one is helping me my contract is in arrears and the sim card is locked but they say I owe them R1500 Vodacom to Vodacom calls but my sim doesn’t work….. they failing me and ruining my credit score. I also share a number with someone else I can’t access my Vodacom app features without it mentioning that it’s thabo Stanley account I can’t do anything online because of that and it’s unfair i get charged money every month and I don’t use the sim card . My minutes keep on moving but my sim is blocked who is using them? Fix this