Potential Hijackers?

I have a private label product that isn’t available anywhere else except for my amazon listing, but there are a few sellers on my listing selling it cheaper than me. How is this possible there’s no other place for them to buy my product except for amazon. Is it other competitive sellers trying to make my brand look bad by giving them a poor experience?

They’re all fbm listings btw and I’ve gotten a few off by sending cease and desists but amazon wont let me contact any more sellers to keep doing this.