Charges

I rented a car for 1 week from europcar. It had a big chip in the windscreen which was on the paperwork. I drove the car away and the chip cracked within a couple of days. (As chips inevitably do)
I dropped the car off and they said it was my fault. I argued but had to catch a flight so told them to email me.
2 days later I receive a letter saying they were charging me £1000 for the damage. Plus they've taken payment for the rental twice!! And kept my £250 deposit!!!
They are robbing [***]. The crack would not have happened without there being a chip, which I did not cause. They won't back down so a £100 rental has now cost me over £1500 so far.