@Jibri dude! First things first. Why did you dump her? There's a reason you dumped her so why do you actually want her back? I'll tell ya. Scarcity, lack of options, fear of not meeting another girl, losing an option for sex without having sex. You said this yourself dude. I don't think you want her back, you just want sex. There's nothing wrong with wanting sex, your mind frame however is wrong. You want her back, for sex... but you can have sex without taking her back and also meet other girls that hasn't pissed you off enough to dump them.
Dumping a girl is much harsher than when a girl dumps a dude in her eyes. This is another topic altogether but she's gone into auto rejection on you because of this. She's had to rationalise that you're in the wrong, it's not her mistake and you're not good enough. If a relationship ends, society will always view this as the dude's fault and very very rarely will a girl take responsibility for her actions. She will only do this in a submit to the dude as a tactic to get what she wants way. She hasn't submitted, she's playing possum dude.
You've now started to chase her phoning and texting, so you look less desirable. You want her more than she wants you, you've lost compliance and she's cutting contact. Sound like you're in the weaker position? You are.... attraction lost, value lost. You've made a decision and can't stick to it out of emotional weakness and desperation. What a stud!! ... yeah she's not thinking that!...
How do you get her back? Meet more girls. Go no contact. Chasing her will almost never work.
Typically go no contact for 30 days and then reengage. The only other option you have on this is temporary insanity. Perfect if you've lost your job or a loved one or something where you can blame your emotional outburst on that, you didn't mean it, it won't happen again and that you're your old self again.
You've got an uphill battle, it's usually better to just meet new girls. You've never fucked this girl that makes it harder, if you've fucked her she's already submitted to you, if you fucked her good she'll be more willing to take you back. Without ever getting intimate she doesn't have much to think about dude.
There's loads of good articles on here for how to get an ex back. But this goes back to my first question, why do you want to?