How to regain control of GitHub repo?

Recently, one of my trusted friends who had access to one of my github repos decided to take control of it and lock me out of access to it, and also wiped all of my contributions to it including any credit. The repository is hosted under a org which I had added him as a owner in, hence how I got locked out of it (I thought that the person who created a organization couldn’t be removed from it by a owner they added, but looks like I’m wrong). How would I go about getting access back to it? So far I haven’t been able to convince them and I’ve poured a lot of work into it and I certainly don’t want all my credit to just be wiped away. I have considered forking it and committing changes there, but the main repo is quite popular and is at the top of the google search results, which means my fork wouldn’t be viewed by anyone.

Thanks!