Apartment Company Charging for "damage to hardwood floors"?

We are living in an apartment complex. When we moved in we were the first tenants, there were scratches on the floor and my husband noted them in the move in paperwork (they were in the dining room). He also called a few days later and said there were further scratches in the hall and living room. He was told by an employee he would note our account and we didn't need to come in. We have lived in this apartment for 10 months, we moved out 2 months early (they allowed us to break our lease because we were moving due to my husband relocation for work). We received an email yesterday saying we owed 1700.00 due to "damage to the floor". We called immediately saying the only damage that was there was what had already been there upon moving in. The manager (he is new and wasn't there at the time) said that we would never have been allowed to move in with scratches on the floor. I asked him why were allowed to move in if we had noted in our paperwork of scratches on the floor? He said those had been minimal and the ones that are there now are much more drastic. How can you scale what is fine and what is not? They say that we have 15 days to pay or this will go on our credit. What can we do? He asked me if our baby was in a walker, I said my "baby" is 2 and she has been walking since we moved in, there has been nothing of the sort there.