Cashiers Again?!?

Ok, I don't know what the problem is with me and cashiers, but it's starting to get on my nerves.

To preface, there is a lunch place nearby where I sometimes eat. Today was one of those days. I picked up a sandwich and a bottle of Diet Coke. The total was seven dollars and change, I gave the cashier a twenty. He handed back the change just fine, but held onto the ten while saying 'Thanks very much' and 'There's your change', while continuing to hold the ten.

First off, give me my change, you loser! I shouldn't have to wrestle it from your grubby palms. Geez. I know he was trying to be funny (and perhaps start a conversation), but perhaps there's a better way to do it?? A way that does not involve pissing off your customer?