Stupid people annoy me

Today I ran over to Subway to grab some food for lunch. I had this gift card for subway so it seemed like a logical choice. And it wouldn't take all that long since I was in a hurry to get back to lounging on my couch. So they make up my subs and ring everything up. Enter giftcard. Then they actually ask me if i want to use it to buy my sub. My sarcastic self really wanted to say "No, I just thought I would take it for a walk then pay with cash. Why the fuck do you think I handed it to you??" Well, clearly they are not the brightest crayons in the box so it takes 4 of them to figure out how to run the gift card. And then they look at me like i am stupid when it is short of the total even though clearly laying in front of them is the balance in c ash. So after about 5 minutes of them struggling with the thing they give me a free cookie. yay cookies. Still not pleased. So finally they decide just to ring it up as a cash sale and figure it out later. I mean if the company offers giftcards is it too much to except that they would actually know how to redeem them when someone wants to use them??