restore or delete a deleted branch

user: solidfire
repo: solidfire-powershell
branch: release

I accidentally created a branch called "release" then I deleted it. Now I'm trying to push to a new branch called release/v1.0 and I'm getting (failed to write). I've tracked the problem down to the existence of the deleted release branch on the repo but I'm unable to recover or permanently delete it. Can you get rid of any trace of it for me?