You’re exactly right. I cannot tell you how many times we have received shocked looks when we have pulled out debit cards to pay for groceries instead of food stamp cards, simply because paying with the food stamp card is the norm nowadays.
If you REALLY want to mess with them, pay cash! Better yet, go to a Best Buy, and buy a $2,500 TV with cash. I did that last year, and the BB Employee literally didn't know what to do when I put the money on his station after he rang me up. The boy looked at me like I had three heads, he looked at the money as if he didn't know what it was, and he picked up the phone saying that he had to call the manager. He hung up and said that he couldn't accept that, and I had to pay up front. The entire situation was both mildly amusing and mildly annoying at the same time.