Gamestop Won't refund me a pre owned Controller.

So a couple days ago I went to my local GameStop and purchased a Pre Owned PS3 it came with all original cables and I assume a OEM Dual shock 3 I can't tell fake ones apart. So later that same day I set up the PS3 and started setting up the wifi and the buttons on the controller kept pushing themselves so the controller was basically useless and it didn't work. So luckily I had a wireless power A Controller that I used on my last ps3 and I have been testing the ps3 and it worked flawlessly. So I went to GameStop earlier today and tried to return the controller but the employee told me that they didn't have any controllers in store and other stores and they couldn't refund me because they didn't know the value of the control. He told me the best solution is to refund the ps3 along with the controller. Anyone know any other solution to this?