I Feel She's Messing With My Head

What to do if your ex is calling and texting you even though she is dating someone else, but not coming over to hangout, have fun and hook up when you invite her to. How to know when to stop asking women out and how to handle their phone calls after that so you can finally get them to ask you out on a date, instead of them acting so flakey and making you feel like they are messing with your head.