Poor maintenance endangering the lives of customers/over charging

I rented a car at Catania Airport and my travel agent had book the cost at a certain rate 619 Euros to be exact for 17 days. In the middle of the trip while I was driving on the highway the windshield became dirt and I switched on the windshield washer. The windshield wippers' motor went 360 degrees came out of its socket and cause the windshield gals to crack on my side (driver side) I had to slow down on the highway ( very dangerous thing in Italy). I tyook it back to the airport explained what happened they wrote it down investigated and concured with what happened gave me another car and sent me off. I come back here and EUROPCAR is charging me for 534 Euros in damages and on top of that (becaused I used a credit card) $248 exchange fee GO FIGURE THIS ONE OUT). These guys are criminals have no concern for the safety of their customers