Why do guys keep texting after its over?

I took the advice of people last time. Told him to leave me alone etc etc. And told 1 mth later he is back to his old tricks. Telling me that he wants to make emends. My heart tells me it is just his ego. I really do care about this guy but my heart tells me that I should not put myself though the situation again. Why would he keep texting me if its over!? I gave him a chance more than once...what should I do? I shouldnt have to change my number, this is a grown man with plenty of other women to bother...