Because, frankly, if you asked any woman if you could come over and they said not tonight, and then you DEMANDED to come over, I’d tell them to stop dating you now.
Why do you think you have the right to DEMAND to come over to her house? You’re just dating her — you don’t own her. She’s allowed to say she’s busy — in fact most women do now and then for various reasons.
When you then contacted her best friend, who you’d never met before, to complain about your girlfriend, you chose an extremely immature behavior. A better response would have been to just make other plans with one of YOUR friends — not hers.
Your girlfriend was crazy to even consider getting back together with you! But when you said you weren’t sure you wanted to get back together, you were clearly just trying to engage her in negative behavior, and now you’re upset that she isn’t responding to you?!
Take a year or two off from dating and try and develop some sensitivity to other people. Volunteer in a homeless shelter or work with veterans returning from deployment who need help with physical disabilities. You really need to get out of your own head and be grateful for the world around you so you don’t keep stirring up trouble!

