Damaged Rim

I purchased a set of 15 inch rims and tyres on Sunday the 15 November at 14:45 from Max Motorsport in Umgeni Road Durban but I did not take the rims and tyres because Supaquick the fitment centre is closed. I checked the rims with the Salesman on Sunday and all rims were in good condition with no damages, re-assured me that they would keep the mags and tyres in their warehouse until I come back on the 21 November 2015 - Saturday , the following week. I arrived on Saturday the 21st November 2015 to collect my rims and not knowing that tne rim was damaged as I had checked the rims the previous Sunday 15 November 2015 and the guys at Max said they tripled checked the rims. I went to SupaTyres to fit on my rims and tyres and only to find out that one rim was damaged, I went back to Max Motorsport and told them about the one rim, they were adamant that the rims were not damaged. I am now sitting with a damaged rim, and they accused myself and the fitment centre of dropping the rim on the floor. I am extremely disappointed and frustrated. What can I do now? As I have a rim that is damaged. How do I know if the guys at Max Motorsport dropped or damaged the mags.