how would i get a number to the car audio guys need to ask a question bout a radio i bought

They all have cell phones. So the only way is to call the number on receipt or buisness card ..there is a security desk ,but I dont think he is going to walk around to deliver messages .best bet is to pay those guys another visit ..hope was helpfull

I would just go in unless the number is on the receipt

Call main number for it.