Sending it back?

Have you ever sent a meal back in a restaurant? I'm watching Jamie's Kitchen in Australia and they're talking about pressure in the kitchen - and one of those pressures is people sending meals back. I could have sent my lunch back yesterday (there was lettuce on my sandwich) but didn't. And now I'm trying to remember if I ever have. I know I've sent coffee back (not hot enough, too strong) but I can't remember doing it with a meal. Not that there haven't been complaints about meals: at Bilson's some years ago "this duck's not cooked" and at lunch yesterday "there's lettuce on this sandwich - I didn't ask for lettuce". It would be easier if I didn't have such an "iffy" stomach - but it often takes me some time to decide on what I'm going to have and as long as something resembling that arrives - I'm usually happy enough.