Comment 1 for bug 34540

Yes. You cannot delete branches.

Long story short, it would be problematic in the general case, but there's definitely a need to fix mistakes. Related to bug 29998.

Your best option in the short term is to reuse the branch for something else: ask an admin to change its name. and product, then change the URL and description. You should not have to ask an admin, related to bug 37476.