BAD SERVICE!!!!!

On the 17 March I went to Bumper to Bumper Malvern Branch to buy a Mazda 2017 model, Sedan Head Lamp and Rear Brake Pads and Discs. I asked the Sales Man twice if he needed my VIN number as I had taken a picture of my Disc. He said No, On 21 March I had ask my Mechanic to come and fit the parts but he informed me that the parts were not fitting. When we went back to exchange or make a swap, they refused as I had misplaced the slip/invoice. I even told them that I can print a bank statement to show them that I had paid for these items but they are refusing. I am now stuck with the wrong car parts. I want to Bumper to Bumper to give me the correct car parts or refund me my money so I can get these car parts from a reliable company. I have also reported this matter to Legal Wise.