Enterprise Car Rentals Ripoff Scam, Austin, Texas

I rented a car from Enterprise from 12/19/09 to 12/26/09 through their website. When I reserve the car thru their website they were asking me several options whether I needed. I clearly gave them my choices on their options.

They emailed me the confirmation number RYZG7G with the price of $235.48.

The day when I pick up the car, I gave them Reservation Confirmation print out. The guy in Enterprise took me out to look at the car for any damage. After that he asked me to put initial here and there in paper. I thought he wanted me to acknowledge of no damage on the car. Even I wanted to read , it was too small characters for me to read. I gave them American Express card.

When I returned car on 12/26/12, a lady in Enterprise asked me to sign for the paper showing $480.98. It was too much different from the original confirmation for $235.48.

I denied to sign the paper and demanded explanation. She said it was for insurance. I was stunned. She told me I put my initial on those. I explained situation that I made reservation thru your website and I did not chose any of those options. She told me that she needed to speak to the guy who asked me to sign when I rent. The guy name Anthony, if I recall correctly, she said, she would have him call me following Monday since he was not there that Saturday.

No one called me since then.

I received your statement and surprised again with their charge. They never called me or contacted me. I did not sign the amount they asked me to pay. I called American Express for disputing. But American Express acting like Collection agent of Enterprise Rental Car. I have no choice but to pay. But it is very hard for me to understand why American Express is not asking to Enterprise Rental Car to provide with Confirmation 

 RYZG7G that I had.

Still followings are my questions;

1.      Where is the contract that I signed final amount of $480.98? How come American Express said I am obligated to pay what they want?

2.      Why the Enterprise Rental Car is not providing reservation paper showing confirmation number RYZG7G which will show all my options that I selected?

3.      When I rent I gave them Reservation paper. Why they need to ask me to put initial here and there if it was insurance or something else. I already denied when I make reservation? They suppose to know what I wanted.

4.      If they want to sell insurance why they did not ask me whether I have insurance?

5.      Giving them my credit card means I am obligated any amount they asking? Thats why they even did not call me for my signature on final amount they claim when I returned car?

If anyone could help me, very much appreciated.