Exceeding storage limit due to a unsuccesful commit

The storage size of my repo was below the 10GB limit until a few days ago, when one of my collaborators tried to make an unsuccessful commit to it. The commit failed, but the storage size became 21.2GB still! I tried to cleanup the repo from gitlab.com, but failed.
Is there any way to remove those garbage data resulted from a failed commit? My repo is https://gitlab.com/cycyustc/ybc_tables_before20211014/ (archived).