Bad Service & Damaged Chandelier

I went to the sandton branch on Wednesday, to exchange 1 clear chandelier for 2 of the same size and stock, just different colour. I have not even opened the box. The exchange was fine. Then when I was paying the difference I saw a few declined credit cards slips on the counter. I gave my card only for the cashier to tell me it's been declined. I say what? Knowing I have funds, she makes it out to be me not having enough money to pay. I ask her to use a different cash machines as that one is obviously broken. She makes me call Absa Infront of all the customers there. I made such a scene and the bank informed me it's not my card it's their credit card machine and we must try another one. She didn't even apologize. Then when we got to the car I asked the sales guy why 2 different boxes? He said the one was in a damaged box and he changed the boxes. I got home and thought nothing of it, but after starting to assemble the lights I can clearly see the one is new and the other one not, also damaged. What are you guys going to do? I hope someone of Lighting Warehouse will take responsibility for this poor service and stock.