I would like advice on stolen property

Location: Elkhart indiana I dropped my car off at the carlot I bought it from to be repaired. I handed the keys over to the owner. Well they had it for 5 days and when I picked it up I was in a hurry because I had to be at a funeral that was 45 min away. So I didn't look it over. When my car broke down I was finishing up moving and had a bunch of stuff in the trunk. I called them and of course they denied it and gave me $230 but I know that's not enough and I'm still really upset