Help with FedEx claim......What would YOU do?

I sold an amp that had a purchase price of $3,000.
Went to FedEx, filed out the ground form, indicated $3,000 declared value, paid, got my receipt, off I went.

The unit arrived, TRASHED, complete original double boxes, bolted to a piece of plywood, yet somehow the unit was destroyed!!

After 4 months, FedEx decided to pay the claim. They did, but paid $2,000. Even though I indicated $3,000 declared value, the person taking the package only charged me for $2,000 insurance, FedEx is taking the side that:

"you only paid for $2,000, this is all we are paying"

which seems illegal. Has anyone come across such luck that I have been blessed? What was the outcome.

Thoughts or views also welcome.

What should I do? They have admited fault by paying the claim. Is it the shippers resposibility to VERIFY their employees work?

Dan