When I execute a
git svn fetch
from my repository, it returns nothing and doesn\'t update even though there are new commits under svn.
I believe you want git svn rebase. This is different from git pull, but similar in that both involve two steps (fetch from remote and then rebase or merge).
You can also rebase only already fetched commits:
git svn rebase --local
If you have local commits that are not yet in SVN, git-svn will replay (rebase) them on top of the newest SVN commits.