What do you mean by “our domain”? Why would you think that you have any claim whatsoever over a name? I am assuming you are relying on a trademark registration in a particular class in a particular country? Or are you simply relying on the fact that you have a domain name registered? Owning an ENS name, even one that is identical to an existing trademark or domain name is not trademark infringement. Trademark infringement requires an infringing action by the owner of the name — simply owning a name is not an infringing action.
ENS is a completely decentralized protocol. The maintainers of the protocol will never do anything to provide preferential treatment to anyone during the registration or renewal process. Even if they did, there is also the obvious problem of deciding who has the stronger claim to a name. Is it the person or company that owns the .com or should it be the .org? What happens when there are conflicting names in different countries? Should a .co.uk have a stronger claim than a .com.au? ENS is not going to turn into ICANN.
If you have a strong claim to the name, as you seem to think you do, get in contact with Opensea and request the name be removed from the website. Short of buying the name from the current owner, this is the best course of action here. Without Opensea there is very little chance that the name ends up in the hands of anyone else.