If you've been blacklisted by another member, unfortunately, there's nothing you can do. Blacklisting is up to the individual trader – we don't ask them to explain their reasoning, and we do not contact them on your behalf.
Being blacklisted just means you won't be able to bid or ask questions on any listings created by that seller.
Other traders cannot see that you have been blacklisted.
To add or remove members on your Blacklist, check out your options.