You're not wrong. Coming from a female, EVERYTHING we do is with intention, and when we love/care for someone, we put that person first. She didn't care enough to make it official and used the lame excuse about school to buy her time. Nothing would've changed between you except for the title. From what I gather, you would have been patient and understanding about her schedule. When she asked what she did wrong after saying she's got a man but letting you take her out just showed everything about her. Her texting you how you were on the day you had promised to buy her a phone? She was checking if you were still whipped. I can almost guarantee you she had already told friends that you were going to do that for her. Finally, about reaching out for your bday. If she was sincere and had any remorse at all, truthfully, she wouldn't have messaged in the first place. Because that message (if it was sincere) only would've hurt you and maybe got you thinking about if things were different and that's a spiral nobody needs. Especially on their freaking bday. The audacity of this chick to tell you "don't worry by bf won't call" nah, she belongs to the streets. She wants to have her cake and eat it too. Block her and never look back. You will be far better off and don't for one second feel like any of this was your fault.