I booked my reservation from Hotwire and paid it i...

I booked my reservation from Hotwire and paid it in full. When I came to Dollar station to pick up a car Lady released a car shout telling me that she did and upgrade and charche me extra $300. When I called them they said you need to read a contract. For 10years of renting cars first time is see how this company is just a reap off.