He even accused me of doing the damage myself to get money from him WTF !!!!
I am afraid, this can be quite common from dodgy sellers.
I had a similar incident a few years back where the seller made multiple mistakes, resulting in damage etc. I too was met with a barrage of false accusations and abuse.
Eventually I simply called up my credit card company and sent them the information.
They refunded the money, and the seller came crawling back with a less venomous tongue.
But got into a hissy fit when he realised he would need to both pay and arrange the return shipping.
Since paypal appear to ruled in your favour for a refund against the seller (against the sellers wishes)
Its clear a judgment has been made.
As others have stated, don't under any circumstances arrange shipment of the frame back.
If you wish for the seller to have the frame returned, inform the seller
they will need to arrange for its collection via courier or shippers account number. Nothing else.
The seller will have to arrange everything, and pay for everything direct.
As any payment made to the buyer to cover the shipment could cause future problems.