ASIN I created 7+ years ago, with photos I took in studio, is now under someone else’s brand and I have to ask them permission to sell on Amazon

I feel like I’m in a Kafka novel at the moment. I have a small business in a niche product and years ago began importing supplies to sell on Amazon for that product. I initially used these only for myself, but then began selling them on Amazon and they sold. They sold well

So, ever since then I’ve been selling them and slowly introducing related items as well. Over the years I’ve seen competitors start selling as well as the market had been underserved when I began

Just recently I found that the ASIN I had originally created, and for which I took the listing photos, wrote the copy, etc, is now listed under another company’s brand name, and when I went to replenish inventory I found I can’t

So I call support and spoke to someone who informed me that yes, I did create the ASIN, and yes I have to ask permission to sell now

I am at a loss