The previous poster was correct...your parents homeowners insurance should cover any damage to your personal property, but they need to contact their insurance company. In the off chance that you are independent of your parents, it is always good to have rental insurance. When I was an undergrad, my parents USAA policy covered me in case of loss.
Here is a good article.
http://www.bankrate.com/brm/news/insur/20030109a.asp
I agree with being sure to document the continued problems. Photographs, certified letters (so the recipient has to sign for the letter stating damage) and make sure you have everything in writing from the names of the people you speak to as well as the dates of complaint.
Good luck!