Stress Free Property Management

I was put into collections for a house that I moved out of after my lease ended. I was charged for bogus repairs as we as my deposit held. I rented a house in 2015 from SF for a year, upon my lease ending SF offered me a larger property because of my good rental history. I cleaned the house fabulously and moved to the new home that was still a SF property. I was told my deposit would be returned in 30 days but then received a notification saying I owed 1500$ On top of my 1400$ deposit they kept. I called and the amount owed was removed. I stayed in the new home until 7/1, upon moving I again cleaned and repaired all that needed it. I never received a refund or an explanation of why for the last house but I have gotten calls now from collection agencies saying I owe 2000$. The house was sold prior to my move out date, I know because I was offered an early move out date from SF around 3/1 so the new owners could take possession of the home. The home was moved into a week after I left & no repairs or cleaning was done. I had wind chimes that were in pieces from hanging by the front door so long that are still there now a year later. My children had stickers on their room windows that are still there. I left a lawn chair on the porch and it also is still there. It's hard to believe they would've done more cleaning and not gotten rid of those things. I also had an exit inspection done that shows no damages just normal wear and tear from 3 years or residency. I would like to have the false bill removed from collections.