Wrongfully Withheld Security Deposit

[NewRenter]

My question involves a security deposit in the State of: WI

I recently rented a house on a lake for a weekend. I paid a $500 security deposit and now the owner is telling me that they are keeping my deposit because of damages. The damages they are saying were already damaged when we got there, I have 5 other witnesses who can attest to that. So far I have not been given any evidence that they can prove the damage wasn't there before we got there. Now the owner isn't returning my calls and I'm very worried that I won't be getting my money back. Also the door was unlocked when we got there and no one was in the house, so I don't think they can prove without a shadow of a doubt that I did the damages. Any help is extremely appreciated. Do you think I have enough for a legal case and enough to win? What are my options?

[Mr. Knowitall]

If you can prove the damages were preexisting, the question of whether or not the door was left unlocked is irrelevant.

If your landlord won't return money he owes, you can sue him for the balance in small claims court.