Complaint Review: Alamo

Rented a car from Alamo at the Kansas City MO airport, picked the vehicle out from vehicles kept in an open air lot.  Night before I returned it, I stayed 2 miles away from the airport it hailed.  I did not notice any damage to the car.  Returned the car to the airport the next morning.  Alamo Representative walked around my car and said I was good to go.  

Weeks later I get a notice that they are asking me to pay $2,655.00 for hail damage.  Sent me pictures that had many hand-made green circles indicating what they said was damage, but no indentions or missing paint could be seen within the circles. I will never be renting from Alamo again.  I will lose my 15% "no claims" advantage if I turn this into my insurance.  I would like to know what will happen if I just do not pay them?