Once you give up or stop trying you'll be more attractive. But you need to offer a solid reason... maybe not for everyone, but for someone. As poor as this sounds, you just need 1 girl to solidly like you (even if you don't back), then there's a good chance some other girl will notice and get jealous or competitive which can make things interesting for you.
Otherwise if you're a total retard, just use a whoopee cushion in the cafeteria next to a group of these girls and then say "was that me?" and say to sorry to the hottest one. She will remember you after that.