There is a small "Contact us" link on the bottom of the page. Insert the link to the submission, give the admins a chance to recognize, that it is really your voting, and ask for a manual editing.
You can vote multiple times. This is useful e.g. if a submission has been improved in a newer version. When I observed it correctly, this works partially only: For the average voting for a single submission, only the last vote of a specific person matters, while all votes are included in the total average over all submissions. I think, that this is confusing or a bug. But less than 1% of the downloaded files are voted at all, so I think it is not an urgent problem.
