my car was stolen and we were at fault due to we didnt have

my car was stolen and we were at fault due to we didnt have the key and the insurance found the car and key and said we were at fault. we agreed to pay back the difference when the car was auctioned off. it has been like 6 months since we have heard from them. I did recieve a letter stating that we agreed to pay back the difference and was told that our case was at usaa's surogation department and have heard nothing since then.