It happens all the time. Talk to the volunteer coordinator, campground manager, or whoever is in charge. Be polite, respectful, and honest. Let them know that you aren't happy and why.
It could be that they can make changes. Sometimes, just a few small changes can turn a bad situation into an enjoyable one.
Sometimes, the best thing to do is simply move on. But, do talk with them first. Arrange an early departure date, rather than sneaking off in the middle of the night. If you are miserable, staying probably isn't good for either you or the campground (or wherever you are volunteering).
