I moved out of my co-op apartment the coop is keeping my 1200 dollar refund?

I moved out of my co-op apartment after living there for 14 years and the co-op apartments is keeping my 1200 dollar refund because the paint on the walls was textured paint and they think I did it but the textured paint was on the walls when i moved in 14 years ago and they were saying they didnt have a record of it and the office has all new people including a new office manager and they claim they dont have any record of the walls being that way and they are keeping my money for something I didnt do. what can i do legally to get my refund back, I live in michigan. and the board members are probably to old to remember becasue they were all old when they interviewd me 14 yrs ago. Thank you