We recently received a letter from one of the manufacturers:
We, *******, do not recognize you as an authorized reseller of our products. You are violating copyright and trademark by purchasing from unauthorized suppliers. We are continuing to gather data on all unauthorized resellers and reporting them to Amazon. You may have purchased from an reputable dealer, but it doesn't mean you can resell on third party marketplaces like Amazon. You do not have a written contract with us, the manufacturer, to do so.

We 100% sure that the product we sell are original and can even do an independent testing. We received a letter from Amazon that: We may let you list this content again if we receive a retraction from the rights owner.

We have right owners email but they refuse to retract the letter.

Is anything we can do on legal level with the company who sent this request to Amazon. I guess we have rights to sell product if the product is original.