My question involves landlord-tenant law in the State of: Indiana

Hi,
I subleased from a girl "M" last year for a one bedroom in a 4 bedroom apartment. The two girls "Y" and "R" who continued to live there constantly invited their friends staying over, used my personal items, and trashed the house. Me and another subtenant girl had to keep ourselves in the bedrooms and never used the rest of the place.

Two weeks before the lease ended, I cleaned my room, ready for check out. I came back a few days later, someone had broken into my room (it was locked) and "lived" there. It looks like one of the girls ("Y" or "R") boyfriend knew that I was not there and decided to use my room. I called the police and filed a report. I also told the manager in the rental office, she said I'll be fine but two months later, I received a bill from them charging for the damages. I tried to resolve this problem with the manager explaining the cause, she said she knew the situation but still insisted me to pay. My questions are:

1. The management knew all about the situation. They have records of "Y" and "R" in their file and they even described the girls "mentally ill". But I had to pay because I signed the sublease . Can they hide all this information and not inform me when I signed the sublease? Or charge me for the damages I am not responsible for?

2. I didn’t see the master lease when signing. All I signed is a sheet of addendum without any details or rules and terms. The manager even refused to show me the master lease when I asked (after moving out when I tried to resolve the problem). The addendum has the wrong date and name (the name of the previous tenant "M" instead of mine) in some part. Is the contract still legal without me initial the master lease or with the wrong information?

3. I only lived there for 4.5 month. The monthly rent is $300, and they are charging me a ridiculous amount over $1,100. Is there no limit of how much they can charge? They don't require any security deposit but $800 non-refundable redecorating fee from the original tenants. It looks like the original tenants would "take care" of the damages when I signed. The manager refused to tell me how much they charged "Y" and "R" and even said she knew they wouldn't care about it.

Should I sue my roommates for the cause of damage? Or should I sue the management for holding the information of previous damage reports in file? Is the paper I signed illegal because they didn't show me the contract and the date and the name are wrong?

Thank you very much for your time.