as title says, this is constantly a problem with different girls.

Im in school, my dad owns a beer company and i get handed cases every weekend so just as an example i may casually talk to a girl then tell her she need sto help me drink this beer. She hits me up says we can hang sat, but ends up hanging with her friends i get it, i see her at bar she in person tells me we can hangout monday.

I told her when i get off class, she says she has a bunch of homework. She's not saying no but to me this is avoidance behavior.

How do i handle these types of situations and make sure that she comes over, rather then avoids. If she's pulling away when we are trying to be hanging out is this some sort of test? Cause alot of women seem to do this, and my typical response is, ill wait after they flake once ask again and maybe if i beleived their was something ask a week or two later, then i give up. I don't invest too much effort in girls that aren't interested, but given this has happened several times, im wondering if i am doing something wrong. If it was a test, wouldn't the goal be to prove that your not needy? which i try to keep the texting minimal and feel like i do ok. But at the some time, if its not conssistent its never gunna work I wont ask her more then 2 maybe 3 times if it doesn't go anywhere.