Sold a used appliance

On the 26th of February 2020 we went to Game in the waterfall mall in Rustenburg and we purchased a Genesis wet and dry vacuum cleaner from the Verimark section, it was late when we returned home and on opening it we found that we had been sold a used appliance. The next day the 27th we returned it. Hope / Dimakatso the sales lady said she was upset as this was the second appliance that day that had been returned used, the other being an upright vacuum cleaner and she claimed that this was how it was received from the Verimark head office. On Friday we received a replacement but on opening it there was a thick packaging at the top of the box and the packaging was missing when we received the first one I had asked her on the 26th as to why the first box was open and she had rep**** that she had opened it to check that all the parts were there. When we returned it the following day I checked the display model thinking that I had been sold that one but I found that the display one had also been used ,so I fail to understand how a used appliance can be sold as a new one.