I was renting and my landlord had prop foreclosed and wont return 2000.00 dep.?

I had a 2 year lease with option to purchaseat they end I didnt want to have to move again since I have 4 children which is why I took the option. I paid every month timly for 1 year and the property was foreclosed on because the land lord didnt make the payments I want to sue the landlord for damages and expenses for having to move & my deposit, any body have a good opinion on this