Buyer demanding refund

Hi, I am located in FLORIDA and i recently sold my electronic scooter that I haven’t ridden in months. I asked 250 and the person offered me $200 and they would pick it up that day. The sent the money but didn’t come get the scooter for 2+ weeks.

They are now saying that the scooter battery doesn’t last long enough and they want their money back and to return the scooter.

I don’t want to give them a refund and I don’t want the scooter back. They said they were going to file a suit in small claims court.

Location: Florida

Can they do that? No contract was signed when this sale happened, am i obligated to give them a refund?