Bad service from Vodacom

my contract number was allocated to a prepaid client. I logged a complain with Vodacom on the 1st of January and on the 11th it was still not attended to. I called them and wrote to hello Peter.com. on the 11th I spoke to Khanyisile Zulu who promised that a new sim card will be delivered to me on the 12th and I must send her an email to do a sim swop. Friday late the sim card was still not delivered and I sent her an email of which she responded by asking me to call ********** 726 for follow up and I was promised the sim card will be sent on the 15th and that never happened. today I am still sitting without a sim card and I am paying for this service which I cannot use. every month my account is debited and it will be debited again this month whilst Vodacom cannot resolve my issue. They cant even explain how t=did my number end up with another customer who is using prepaid. They have blocked my sim card, I cannot use it but the prepaid client can use it. I want this matter resolved asap and my account must be given a prorata because its their fault to start with. since I was told my 1st query was gonna take a month I am thinking they are just buying time.