AVIS International AVIS Quote in USD but Final Bill in Euros Internet, Internet

We rented a car on our recent trip to Europe and I reserved it online.
After spending about 14 hrs. on the aircraft we got off in Frankfurt and went to the AVIS outlet where I presented my reservation that I had printed for them. I signed the documents that they presented and we got our car and were underway.
When we returned the vehicle I wanted to see what the final charges were but they said it was all taken care of and my VISA card would be billed (not showing me the final bill).
Not until I looked at the VISA bill did I realize that somewhere along the line they had changed the charges from USD to Euro which at that time were almost 50% higher when converted to our currency.
I contacted AVIS International and was given a claim number. 

 Two weeks later I recieved the rental agreement from Germany that shows what I had signed (In Euros)
I contacted AVIS International again and they told me that the international office was not even connected to them in the USA but I would have to file a separate claim in Germany.
My take on this is that AVIS is engaged in false advertising and taking advantage of weary travellers that are tired and will just agree to whatever terms they present when the customers show up.  After all, who wants to be stuck at an airport without wheels when you have booked ahead to be certain you have transportation when you get off the plane?