Repo size is wrong. Can't fix it

Hi, we have a repo, https://bitbucket.org/gzagara/ecn2-solution

And it now displays this message: This repository's size is over 1 GB. Read more on how to reduce the size of your repository.

We cleaned and closed any branch but the repo size seems still wrong. Cloning via VS stops at 1074 GB while downloading sources from site reports about 300 MB which seems matching the real size. Can you lease help?
thank you