Vodacom billing me for sim cards that i dont have.

I went to Vodacom Cradle Stone last year in 2014 for a 3G card and the lady suggested that I can do upgrade as I am due...we filled up the forms and while she tried to upload in their system....the system couldn't allow them because my account was in areas for that month and according to their Policy they cannot give a contract/upgrade while the account is in arrears.. I then managed to pay these arrears in June when I had money and when I decided to close this account they told me the balance is about R10 000. I was very shocked to hear that tried to explain and was sent from pillar to post telling me I need to pay. I did the statement from the police station as they requested from Vodacom call centre but I am not winning they just want me to pay and unfortunately they never gave me the sim card. The sad part is that I am being harassed by their Attorneys on a daily basis and when I went to Vodacom Cradle Stone mall....the sim card shows that it belongs to somebody else.