UPS Question/Problem

I bought a center speaker from a seller who stated he'd insure it for replacement value of $1,600. I paid $600 because it was used and had a "nick" on one corner. Speaker came in horrible condition, don't know if it's shipping or deceitful seller, but seller claims "as new" when shipped. Speaker trashed due to broken cabinet. Called UPS to make a claim, they say the seller has to file the claim? Now seller says he'll file claim and give me my $600 back, and I presume keep the extra $1,000!!! He's now stating he only insured for $600 and doesn't remember telling me otherwise, though I have the email to prove it. This seems like fraud on sellers part? Don't I now own the speaker since I paid in advance (including shipping and insurance)and received shipment? I bought and received a speaker, now I get tossed aside and the seller makes an easy $1,600? This doesn't seem right. UPS screwed up MY speaker, aren't I the one due compensation with a replacement speaker?