Our own products are gated by offshore seller

Hi everybody new to this community. I’ve been selling on Amazon for about 10 years now and had problems with sellers trying to steal my brand.

I am reselling parts from a local manufacturer through an exclusive contract to sell on Amazon

I was able to branded as my own before Amazon changed the rules We never got a trademark and the manufacturer never got a trademark even though they’ve been in business since 1965

A seller, which I think is based in India, suddenly claimed ownership of these products, even though they have nothing to do with them and gated them . The same company did the same thing a couple years ago and were able to reverse it. Our manufacturer’s name is actually on the product. I complain to Amazon and they refuse to do anything saying that the company that gated the products own the trademark even though they don’t.

Can I send a cease and desist to amazon for fraudulent branding? We are in the middle of getting a trademark now, but it’s gonna take some time.

How do companies get the brand stuff even though it’s not theirs I don’t understand how this happens.

Thanks in advance