I think the seller is wrong here. Firstly left for a few months. Then someone replied left for few months still got battery, suddenly become charged for awhile. Sounds like it was made up. How can you blame your customer for coming back to you ONE day after selling saying that there's a problem with the item you sold? It's one day ffs. Not a year later. And lastly to the buyer, you're at bigger fault for threatening. I think it should be dealt professionally and not through threatening and all. I wouldn't stand on anyone's side here, BUT if the buyer didnt do the threatening then the seller is wrong.