There are several signs that rabbits use to show displeasure, and the signs depend on how unhappy we are, and for what reason. A rabbit that is scared or worried might have its ears back against its head but turned outwards to listen, or ears straight up and pointing forwards if its listening for danger (or for lops, ears turned forwards at the sides of the head), and may stamp its foot and run away to hide. Rabbits can be scared by sudden loud or unexpected noises, and maybe something that the rabbit has noticed that you aren't even aware of as they are very sensitive. The foot stamping is a way to warn other rabbits (and that includes you) that there might be some danger. If your rabbit is doing this, don't rush up to it or try to pick it up - you might scare it more. Approach slowly and put your hand in front of the rabbit so it knows that it's you, and stroke its head to reassure it. Occasionally, this also indicates grumpiness - Jemima stamps her foot if breakfast is late...
If you have done something that your rabbit doesn't like, it will make it very obvious that it's not impressed with you. The signs of this start with sitting near you but looking the other way as though there is something much more interesting over there, or slightly more serious is turning its back and completely ignoring you. If you have offended that rabbit even more seriously than this, you will probably see the rabbit flicking its back feet up at you as it runs away. Some rabbits also grunt when showing signs of displeasure. Any of these signs mean that you have some grovelling to do - sit near the rabbit and try to give it a stroke on the head - be aware that if your rabbit is very unhappy with you, it may take offence at you stroking it without being invited to, and then you will get the back of the rabbit to look at again!
Like most of the rabbit language, you can use these signals too. If your rabbit is being naughty, stop it from doing whatever its doing and then turn your back on it and walk a few steps away. Don't look back, and you will probably find the rabbit at your feet trying to make friends again. If you want to try running away flicking your feet, make sure that no one is watching!