Midrand Builders Warehouse/Online selling Used electric mowers

Bought an electric mower & line trimmer combo online to pick it at Midrand Builders on 24 December on Order ***. Picked up the order on 6 Jan & asked online why boxes were sealed with cellotape. Took my boxes & shipped then on courier guy to Schoemansdal at home. Got Home on 27 Jan and opened the boxes only to find the line trimmer was used and had a red sticker with Redirected. Why sell a used item rejected by another customer to me. With all the shipment who is to pay for the return back for exchanging this Line trimmer? Garden department of Midrand Builders Warehouse please sell me a new trimmer that I paid for not another customer rejected item.