OK I asume you are a woman........so no one has taught you to do anything for yourself.
First off Do you know what Home Depot, Loews, or Wal Mart is? Its this biggg store where you can buy a few smoke detectors for what $20 each, and hang them on the wall, and its YOURS, yo can take them when you leave...oh make sure you have a battery in them....
Second do you know what a hammer is? NO NO NO.. NOT MC Hammer but a hammer, maybe $10 you can pound the nail back down and gusss what its usefull for a lot of other things too....not to mention screwdrivers and pliers
Third ...you left without getting a copy of the lease with your keys... I guess you will never do that again, now will you?
Fourth.you have reciepts for the rent right? You didnt pay her in cash, now that would be stupid right?
Fifth.. How much is the total rent? Do you have proof of that? Did you see the ad in the newspaper.....well go to the library.. and find the paper with the ad and make a copy.
Sixth.....$500 each for what.. explain? did you pay last months rent?....OH se wants to raise the rent she must give you 30 days notice in writing, and since you have no copy of the lease....you might as well move by the end of the month
Seventh..did you send a certified letter return reciept, demanding the water heater be fixed in say 5 days or you will call a repairman out and have the charges deducted from the rent?
You should look into suing her in small claims court for you deposit back, cause she wont give it back.
Now you have sum lernin to to do, go use this thingy calleda compooter and search your state laws and edddukate yorself so you dont get ripped off again.