I'm wondering, if you go to a restaurant and they bring you something other than what you ordered, even if they fix the mistake, do you expect something for your trouble?
It depends on how much inconvenience the mistake caused. If they make it right quickly, I generally don't expect a discount. If I sit without food while my family eats because they are having to cook a whole new meal, then I would expect my meal to be taken off the bill. It's all a judgement call.
Agree with Kelley.
Although my husband and I refuse to accept free meals. And we explain to the manager, "While we appreciate the offer, we did not make this complaint to get a free meal. We brought the problem to your attention so it could be corrected."
We want our issue to be taken seriously and not shucked off and thrown in the pile of "oh, we gave 'em a $5 coupon and that shut 'em up!" So if we're not "bought off", then they know we are serious.