Family Dollar

I ran in to get a couple of packs of taco seasoning. The cashier had on a Bluetooth headset talking to someone about an unknown sister that had made contact with her as she checked out customers. (Drama customers should not have to listen to.) I handed her a $20 that she laid on the counter and marked with a marker of some type. Since it was $3.17 I thought I would see if I had change rather than her having to count out change. It's difficult to get change out of my wallet so I placed my loose change on the counter and separated seventeen cents. I picked up my other change to put back in my wallet and she stated, "Pick it up and hand it to me, please." And I looked up, surprised with a "What?" Her reply, "Pick it up and hand it to me." To which I stated, " You have your pay." She did hand me my $17 with a parting, "I would not do you that way." And I'm thinking, what way? Is there a rule that money must be placed in the cashier's hand. If so, please post it.