Seller advice on returns.

I own a kindle scribe. I haven't really used it and finally decide to sell it. I listed it for $200 which I original paid $400. I was so excited it sold in a few hours. I ship it out right away Monday morning the next day. Two days later the item was received. The user was happy stating that he gotten it. He told me he had lost his kindle a trip. I was surprise he didn't purchase a scribe 2 on prime day. I didn't really think nothing about it. 4 days later he reports the item as defective. He stated it wouldn't write well. I barely even touch the scribe and didn't write on it. Ebay is giving me until July 30 to take it back. Should I just take it back. I don't know what happens if I don't. I read on here that they will refund the item to the buyer and they don't have to send it back. I just notice he open his account 7/17/2025. I should have cancel the buyer right away. Now it seems likes he trying to get a free kindle or something. I reported the buyer but no response. I also message the buyer. Telling him no refund it wasn't never defective. I haven't heard from him what should I do. I haven't sold on ebay for a long time. I been a member since 2003.