Seller refunded now refuses

I recently bought a watch two weeks ago. The watch arrived 4 days ago. Yesterday I filed a claim saying it wasn't as described. I paid a few thousand dollars for the item and it had scratches on every part of the watch that pictures weren't shown for it, ie the seller "I feel" misled me. He had no pictures of the caseback or the bracelet. It is scratched to hell. He also said watch came with box and papers which means in the watch world the warranty card which adds substantial value. The warranty card was not in the box. Fast forward he sends me a condescending message back asking why I waited so long to return it, the scratches could be buffed out, and the warranty card didn't matter. He then accepts return and I go to bed. I just woke up to another message saying it was by accident and he is escalating it. Repeats over and over for me not to send the item. Which I'm not because I want this to be official. What should I do?

TL;DR Seller sends item not as described, accepts return, and then refuses to accept it.