Avis Thrifty Avis and Thrifty rental car left us stranded Nashville, Tennessee

I recently made a reservation 2 months in advance of our trip to rent a mini-van to go one way from TN to Colorado.  I called three times to insure I understood the debit card policy thoroughly and was told I would be charged 100% of the rental up front plus a 250.00 deposit which was fine.  upon my arrival to the airport in Nashville I was denied the car even though I had the entire amount available on my card and was left stranded with my child in Nashville. I was in tears and had to have this car to move my family across country as a single mom and knew noone in Nashville. I was unable to find another mini van and had to rent a very small car and was charge three times the amount plus a one way drop fee costing me near 2,000.  We were so crammed and uncomfortable and our trip was ruined needless  to say dangerous because we had so much stuff and no leg room at all.  I couldn't believe what they did to us.