Unfair!!

I am being held repsonsable to pay for something I did not buy from this store - R7000, when I went to Price and Pride the lady count not find any record of me on there system, not even a garnishing order, this is so unfair as I know that I did not buy the item, no paper work as all paper work after a few years are destroyed so what must I do to get this off me, if there is someone that can help me I would really appreciate