No Managerial skills

I had received a gift of three dresses which was purchased from a mr price store in durban gateway. The items was not fiiting well so I decided to have them returned.I went into the mr price store in ballito and couldnot find any items that I liked.I asked the cashier if it was possible to give me a voucher for the items so I could purchase at a later stage.The manager Meena came to the till an said that I couldnot get a voucher,because the items was marked down to such a low price an I could have purchased it at a factory shop an brought it to return.the items had sale tickets that was printed in the store,so how can the items be purchased at a factory shop.she said I had to pick items for the price of the exchange###So I would like to know as a customer if she could exchange the items for something else which I didnot like,why could she not give me a voucher for the same amount.And was the statement she made according to the company,that you can accuse customers of purchasing items from a factory store.As a manger she should have known her items,and as customer who didnot have a reciept the way I was treated was unacceptable.Now I have come home with items that I'm nt even happy.