Undo git mirror

i have used these command thinking to mirror a github project on a directory in our gitlab

 git clone --bare https://github.com/exampleuser/old-repository.git
d old-repository.git
$ git push --mirror https://github.com/exampleuser/new-repository.git

but unfortunately it changed to master and eveything in our gitlab got replaced …can anyone please help me undo the mirror…i have local original branch