Vodacom knows how to ******* their clients

I'm having bad experience with vodacom specially when my contract is about to end with them. If they don't cancel it advance airtime is being purchased on the vodacom Sim that no one is using because that Sim is placed in a spare phone that's for emergencies and that Sim card gets airtime every month so there's no need to purchase advance airtime. Firstly my contract that expired in November and had canceled in October was never canceled after I've phoned continuously every month twice thris only 9mnths later they really canceled it,was never reimbursed for their mistake its just every time we apologize I'm sorry for the inconvenience that's all just bull. The problem I'm having with them now is the advance airtime that being purchased on my account it was a R4 and then R45 it does not sound much but who ever is doing it was starting at a small amount and saw that i did not pick it up and then the R45 and when i spoke to someone from vodacom the guy said it might have been a family member like really please dude you making me frustrated now and I'm going to start using foul language here,he best answer was ill block it and then no one will be able to buy advance airtime again that's not the answer i want investigate and find out where, wjo and how. It's like they make a mistake but you as the client will still pay no matter what. This contract of mine is finishing the end of the year and then I'm really done with vodacom they can go sleep,i do not want any calls from them to say what a great loyal customer I'm am because I'm not their customer. Vodacom can go and fly but I'm done with them.