The store cashier and the grocery wrapper is very rude

After I checked out and as I'm walking out of the Stater Bros. store with my groceries, the cashier who handled my transaction and his grocery wrapper both laughed rudely so loud that the whole store's front counter can hear them, they're rude, and either no class or just pretend and purposely want to be rude. The Stater Bros. store # is 106 and the cashier who handled my transaction is Matthew P on 06/09/15 at 21:58:15. He shouldn't be allowed to work there because he did this, it's a discrimination. If it's not a discrimination, then show me the legal documents which allow them to do this, if no show document, then it's always in the "grey" area, and they heck ought to get fired or else I deserve the right to have the police catch them either or sue them. Bunch of brads working there in the store, gosh, give me a break, bunch of brads.