So i went on a trip with a friend and his friends 2 weeks ago, and I found one of his friends attractive and decided to use the PUA materials I've been reading. I played cocky/funny on her and noticed multiple IOI's from her. She'd always sit next to me at restaurants, ask me questions whenever I purposely didn't talk to her much, and laughed at everything I said even if they weren't funny. (just some of the IOI's) I think things went pretty smoothly in this stage. The funny thing is, she'd kinda do the same thing I'd do to her. (playing push-pull, hard-to-get, neg, etc) I decided not to make any move during the three-day trip since I didn't want other people to get uncomfortable in case something goes wrong.

I set up a dinner with her for day2 last weekend and took her to a nice restaurant. I made a mistake by appearing less cocky/funny and more serious compared to how I was before, and things didn't go as well as I hoped. I initially wanted to do something afterwards and k-close but she seemed pretty tired so I dropped her off. (she usually goes to bed really early for work) We both played cocky/funny and hard-to-get, and gave a little bit of false disqualification. I really thought things weren't really going anywhere since none of us was willing to make the first move. I texted her 2 days later, and she seemed to be very excited in her texts using multiple !'s and saying "hahahah."

She has work early in the morning, and talking on the phone wasn't an option due to our work/sleeping time conflict. I've tried calling her but I'd get a text message early next morning saying she was sleeping. So I had to play the text game. I texted her cocky/funny messages at work like every other day so I don't come off desperate. Again, she appeared to be excited in her replies.

Here's the confusion: She has NEVER initiated calling or sending texts, and always appeared (maybe she tried to appear) busy replying to my texts at least a couple of hours late. I've even texted her to call me before going to bed because I wanted to talk to her (probably a bad move) but she didn't call me. I really don't wanna come off as I'm chasing her by initiating everything but she's not really giving me an option. If she just stopped replying or didn't sound so excited in her replies, I'd just drop her and move on but apparently, that's not the case. I just called her again to set up day3, and it went straight to her voice mail. (I have a feeling that she was awake and ignored my call since she told me that she usually goes to sleep late on Fridays when I called to confirm the dinner last week.) I just followed up with a text right after teasing how she goes to sleep so early.

Any tips on girls who seem to be playing hard-to-get? How can I verify if she has lost interest in me instead of playing hard-to-get?

ignore her and talk to other girls infront of her

Like the other guy mentioned, ignore her for the time being. Hopefully she'll begin to wonder why u've stopped texting. If u ask me, i personally think u've been texting her and trying to get into contact maybe a bit too much. U mite be coming off desperate and needy and mayb that's why she's ignoring u. Being desperate mite imply to her that no one else wants you, which consequently lowers your social status and makes you very unattractive. Step back a bit and maybe make sure she's aware that ur a busy guy too, just make urself seem more valuable, and that there are plenty of people who would gladly spend time with you, particularly other girls i.e. photo's uploaded onto facebook could help.

I had the same problem as u, but the above helped me sort this out.
If she genuinely feels attraction towards u, she'll get into contact sooner rather than later hopefully wondering why u've suddenly stopped giving her the attention she wants.

Hopefully this will help.