How to get a copy of a credit card receipt?

I have a corporate credit card. I had a bunch of receipts from my American Express card in the car. Long story short, the receipts were destroyed after a flooding of the car. My company won't pay the expenses without the receipts. I called AMEX to get copies, and they said they don't have any? They said that they can request them from the merchants. I called the places where I used the card, and they said they don't keep them either??? Am I basically out of luck, or should I fight this until I get answers? I'm looking at paying $1,600.00 so its worth my time.