uhhh.... you didn't take a L first off.
second, who said that because she walked away and you complimented her that you can't talk to her again or she doesn't want you to talk to her. don't assume.
third, talk to her again. however, this time talk to her without bringing across the idea that you want to date her or have sex with her. if you move like that, of course, she's going to shut you down because she's going to think that you're using her ass. talk to her as if she's a buddy of yours. if you get friend zoned, then cool. you don't have to always to treat every woman you're talking to like she's a love interest or a f*ck buddy. they think that's annoying as f*ck. if she doesn't want to have anything to do with you, talk to another chick.
it's NOT the end of the world unless you make it out to be. it's also NOT the end of the world because a woman isn't interested in dating you for whatever reason. you'll be fine.