VODACOM ARE USELESS

I did have a vodacom contract in 2011 and 2012 so the day Vodacom phone me and say its time to upgrade and I went to the vodacom shop in Klerksdorp in the mall, the lady helped me and I asked her to cancel my contract because my new job gave me n phone to use. So I sign papers and she say my contract will be cancel but my number will not work any more I say its fine then she gave me a new sim card and we rica it there in the shop. So from that day I didn't use that sim card or phone again. Know in 2015 Jacobs Burnard Associates phone me and say I own Vodacom R5674.70 for my vodacom contract.. I phoned her and explain the hole story for her and she just let me the contract was never stopped. Then I phone Vodacom the same lady and she say there is nothing under my ID or my old number but she picked up they gave my number to a bussiness to use know.. For 3 years they didn't phone or sent me any letters to that's very very bad I won't pay that money I did cancel my contract