I haven't really but it has happened.
So, what if you did, what do you do? Firstly obviously have a little cry and say "why does this always happen to you" once you've gotten over that rubbish you have a few options. First, take it to your local camera store. They normally will be working with a camera repair company that will charge a set rate and they will fix your camera for you after a few weeks. In theory, you can pay twice by doing it this way once to the camera shop and once to the repairers, so the price could add up. You could always go straight to the manufacturer, that's what I did.
With any product, you get a warranty. Sadly if the problem is accidental the warranty doesn't normally cover it, some times they do might as well ask first. That's the same when taking the camera to your local store, if it's in warranty it could be covered.
Taking it to the manufacturer you are guaranteed the work is done properly and it's not someone who learnt to repair the equipment by watching Youtube videos. I always recommend going to the source. They made it they should repair it.
Best thing to do is keep your camera safe this way you won't need to go through the repair process. Keep a strap on your camera, always have a bag. it may be weatherproof but keep it out of the water. Safety first.