Repo still full but no files and no history

Reached the size limit of my gitlab repo. Decided to remove all history and all files, so I “restarted” the repo by creating a new repo on my machine with git init and then forced pushed it to the remote repo. Now I’m at a situation where I only have the .gitignore file in my remote repo. Can’t see any history or other branches but gitlab still it says my repo is 9.6 Gb. So the old files are still there somewhere but I can’t see them. Is there any way to remove them?

Thanks, Johan