Corrupt Repo

We have a corrupt repo, https://bitbucket.org/redowl/reference-data-service. We'd like to truncate it back to commit hash a70e06847f543dfe136edb92f774edb6eeba7d9a, but we don't know the best way to do this, and have been unsuccessful via the usual channels (google, stackoverflow, etc).

given it's a hosted repo, is this something atlassian support can help us with?