before leaving the counter, check your items, is it working, any cracks/defects. If its a car integrated item, take it to your car, and straight away test it. If you leave the store come back five days later with a cracked/damaged item, only you know it's the truth. To skeptical others, they could just say that you dropped it on the floor, too harsh on it...anything...so i don't think you can win this case. Unless you can somehow prove. and that imac in garden's thing. you just gotta be more tech savvy...too noob lah, do homework before buy....but still i suppose that salesperson should have informed you....