Angry Seller threatening me

Hey guys, I’ve recently started selling one of my generic products on a popular asin with the same generic product listed. I had a lower price so won the buy box for this item and was getting many sales a day, However the listing creator has it listed under a brand. After about a week he sent me messages threatening to make a claim to “shut down my account” unless I stop selling the item. It is the same exact generic product but his listing has a brand. There are other sellers like me selling the same asin just at a higher price and they do not have the box. I set my stock to zero but would like to keep selling the product. Any advice ?