Where can i buy a Gothic prom dress?

My prom is June 10th, and well i don't have a prom dress. I wanted something maybe ripped up, dark, fishnets? Color is fine also, but not to much. I would like it to go down to my knees, but any length is fine.Websites or stores are good, i would appreciate the help. :3 I live in Michigan if there are any stores around that i could go to?