mr09, your ex could be toying with you for any number of reasons: ego gratification, power (she's got you on a string if you respond to her "pleas"), for the sheer sport of it (unbelievably cruel), her boredom, your vulnerability--but it's seriously doubtful she's doing it for true reconciliation or anything of that nature. You already know you should not respond (don't--you'll regret it, again), so you have to drain all the feeling from the messages and act as if they don't matter at all. Look at what she's doing for what it is: manipulation, plain and simple.

I think I can safely assume you'd be highly irritated and insulted if someone for whom you did not have deep feelings played games with you, so why tolerate this from her? Remind yourself that what she's saying to you, no matter the wording or implied content, is rubbish being hurled at you to get a reaction, and no more. The key to freeing yourself is to ignore her--DO NOT RESPOND, no matter how it makes you feel.

I know when you still have feelings for someone, it's hard to heed words and warnings such as these. But any type of "relationship" you have with her is ultimately unfulfilling, and you have to believe you deserve better, because you do. Don't run in place for someone who doesn't have your best interests at heart--don't run in place for anyone. When you're in a relationship with someone who truly values you for who you are, they won't make you feel this miserable or force you to chase after meaningless bits they toss at you for a reaction.

Don't idealize crumbs flicked at you from someone who can't be bothered to eat with you in the first place. Best of luck to you, mr09.