I accidentally pushed up files from my .idea directory in my Django project which I had in my .gitignore file. I am trying to completely delete the commit from my bitbucket repo
Use git reset --hard 3813803. This can not be undone and works locally as well as remote.
For remote push using git push --force origin master
Have a look at the git docu by Atlassian here.
Let me also quote from there:
Whereas reverting is designed to safely undo a public commit, git reset is designed to undo local changes. Because of their distinct goals, the two commands are implemented differently: resetting completely removes a changeset, whereas reverting maintains the original changeset and uses a new commit to apply the undo.
git reset is the one to be used here, though, because you are asking for complete deletion.