it happened to us few years ago while trying to transfer a rifle from Nebraska to Canada with a FLL.
the seller did not want to ship anymore but forgot to give back the money...
a little chat with the local police and DA changed my life: i got my rifle finally but the Judge didnt follow the recommendation of the local police nor the DA but i got the rifle back.
PS: they slammed his door and wreck his home with a SWAT unit (gun involved)...
try first the local police. they helped a fellow Canadian.