Cannot delete a remote branch created unintentionally

Question

$ git branch -a
* SocialAct
  master
  remotes/origin/HEAD -> origin/master
  remotes/origin/SocialAct
  remotes/origin/social

I want to delete

Answer 1

The below command will delete the remote tracking branch but not the branch which exists on remote

$ git branch -d -r origin/social
Deleted remote branch origin/social (was 26f6f61).

To delete remote branch:

git push origin  :social

This will automatically delete the remote tracking branch i.e remotes/origin/social.