contact fedex and dispute and contest the charges ?

it isn't the same situation, but years ago I got charged like this after-the-fact once when I bought a used frame from the UK.

After a bunch of back and forth it turns out they were using the duty code for a new frame.

Fedex is dealing with a couple of million packages an hour. Crap like this is all part of "the system", no doubt helped along with a variety of unfailable algorithyms.

We all feel for you, brutha . . .