Customer Let Down at Builders Warehouse

I’m building a house in Bluff and I have spent so much money in materials and household goods. I had a true problem whilst visiting Rossburgh store and I had to buy a tyre jack and a spanner. The tyre jack wasn’t suitable for my car as I had to put bricks to make it efficient. I returned the jack to the store but because I had misplaced the receipt they refused changing the items. I pointed the cashier who assisted me but he couldn’t recognize me even trying to remind him as I was at store previous day. I had made two purchases as I had ordered sand and the guy who assisted me with this purchase recognizes me. I showed them both transactions as they were reflected on my inbox and they clearly indicate date and time but they still refused and I had to leave the jack and wheel spanner because I didn’t need them. I then called their customer care last week Friday and I spoke to a lady called LuA