Refused refund

I bought brake pad for a hyundai Tuscon, the back ones and unfortunately they were not the right ones. I went back to them and they said they do not have the right ones. I went to another spare shop and got them. I then went back to Midas to return the wrong ones, they denied ever selling those brakes to me. I had the slip and they said they do not sell that brand and refused to refund me. They brought some on their shelves and told me that's the brand they sell.