After you've paid, you're pretty much stuck. It depends on the apparent reason for it. I would definitely speak to the manager.

15 minutes. After that you could have gone to a dine-in restaurant.

It depends on how busy I am at the time -- usually 10 minutes is about my limit.

Well, I work at a Tim Horton's that share a building with a Wendy's; They are very lazy. They won't even clean the bathrooms. I've heard that other Wendy's locations are the same, so since they put forth no effort, if you are waiting for what you think is a long time, talk to the manager. If they are as pathetic as the staff, go to the general manager, and then the franchise owner. Somebody has to care about something over there.

If you're worried about your food being cold then I would think you want hot fresh food other than getting your money back.

How long does it take to cook some burgers from the frozen patties? To fry a batch of french-fries? If I would have to wait too much longer than that (and I can SEE that things are waiting), I would ask to speak to the manager. If nothing happens there, I would call corporate headquarters and get the franchise owner, regional, or district manager's contact info and call them. Sometimes franchisers have no clue that the people they put in charge are pulling crap like this. Admittedly, they SHOULD, but if no one tells them, and they don't have surveillance they check religiously, how would they know? If it's a corporate run site, things may go VERY smoothly when the district/regional manager is around, and very lacidaisical (sp?) when they aren't. And again, the restaurant manager may not have a clue that those they've delegated aren't doing their jobs. Remember, though... These kids get paid minimum wage to do their jobs... There's not really a lot of motivation, except for doing a good job, and we ALL know that there are many teens, and some adults, could give a crap about doing a good job without the right motivation. (Not excusing it... Trying to explain it.)