Alright, I'm new around here and wasn't sure if this was the right place to post this. [Mods feel free to move this if needed]

Before anyone says I'm an AFC or I have "one-itis" please don't .

I go out to clubs / bars every weekend, spit game and get results. But once in a while I find a girl I'd enjoy getting to know better. I've recently found one that I'm interested in, but I always seem to have the same problem regardless whether it is she or any other girl I finally find interest in.

I'll use her example:

There are 2 very large group of friends, mine and hers (lets call her Susan) and our groups are filled with mutual friends so when we're at this beach town we always go and party together. I met Susan last year and at that time I was having a fling with one girl and she was dating some guy (it lasted about a month). She eventually told me they broke up and then a month later I told her my fling ended. 4 weeks later we ran into each other at the club, that same night I was hooking up and fingering some girl I had just met (friends of both our groups saw this as it was in the middle of the street outside of the club). When I went with this girl to another club I ran into Susan. The girl asked me to goto her hotel but I refused because Susan's friend insisted I talk to Susan, and kept pushing me to do so.

Eventually I did, she asked me if I still had contact with the girl I had a fling with I told her no, she asked again and again until I told her "no now stfu", she seemed relieved. That night we hooked up, had a great night went home together etc etc. It's been 3 weeks since that happened. During these 3 weeks she has been initiating conversations with me on facebook, and on SPAM (a chat app on phones). Sometimes when she knows I'm out partying she'll start texting me to see if I'm having fun (I won't respond, or I'll respond MUCH later). Now lets get over the background and get to the issue at hand.

When I try to ask her to meet up (or any other girl), I get a "I can't I'm doing X with my friends", now I know shes in the middle of finals so I pitched a "since I'don't know when you will be available because of your schedule how bout you let me know of a day your free" type of thing. got 0 response.

My problem is always exactly this, I can hook up with a girl no problem. That girl will chase but when I try to get her to go out on my terms I get blown off.

Any advice would be greatly appreciated.

Call her. Ask her out on date (not on a weekend). If she babbles, turns you down, makes excuses ask yourself, "Do I really think she has that high of an interest in me?". Your ego is getting in the way of you seeing reality.

NEVER ever ever tell a girl to contact you when she has free time. You've just handed over any power you might have had. YOU are the one in control. It's similar to guys giving their business card to chicks in a bar and telling them to call you. Some may disagree, but unless you're an Abercrombie model this never works. It says subconsciously to the girl, "I'm too much of a pussy to ask for your number, so here's my card.".

Did you have sex? I never know what 'hooked up' means. It implies too many things. Tons of girls are down for the random makeout, but the next day is a different story. I'd move on if I were you.

It's possible that it's my ego, but I just see the fact that shes the one contacting me constantly and whenever she sees I'm not present at that beach town she brings it up. Also the fact that her friend was pressuring me to go find her and talk to her during the night made me think there's deffinately some interest (something her friend is aware of and I'm not).
Only reason I do this is because I get tired of asking (a total of 2 times hahaha). I asked once for a concrete time and place, I got an excuse, she was doing stuff with her friends. I sent an open invitation for a concert it was a no response. With no offer for a day that may actually go good for her to meet up.
No, didn't have sex. It was simply makeout, grope and a bit more touchy feely. But I don't think it was "random" she had it in her mind beforehand I'm sure (otherwise her friend wouldn't have pressured me into talking to her instead of sleeping with the other girl). Then we had an instant date to go have breakfast. (Partying here finishes at 7 AM).
Already on it, but I was just wondering if there was a way for me to fix this problem. It seems I always run into it, "flakey women" is it?