My grandma complains a lot too. She can't go to any restaurant without complaining about something. When we get our food she will check what everyone got to make sure it's right. If you ordered a burger with no pickles and there are pickles on the burger it's not sufficient to just take them off- she takes it back up to the counter and demands a new burger and a refund. If the fry container isn't completely full she'll take it back to the counter and make them fill it until fries are falling out all over the place. She's pretty stingy with tips at nicer restaurants too, if the waiter or waitress makes a mistake or doesn't keep her glass more than half full she doesn't want to leave a tip, and if you try to leave a tip she'll pick it up and hand it back to you. You just have to wait until she leaves the building then go back and leave a tip, and even then she knows what you did and she'll complain all the way home. I don't think she's worked a day in her life but she sure is adamant about everyone else doing their jobs to perfection.
Whew, now that I got all of that off my chest I could go for some coffee.