My only responce is:
Rom 11:25
25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
Rom 14:11
11 For it is written, As I live, saith the Lord, every knee shall bow to me, and every tongue shall confess to God.
... and my only response is: G-d's covenant with Abraham was for all of his descendants through Isaac. Since G-d is eternal, and is not a liar, the covenant still applies and always will. Ditto for promises to Isaac, Jacob and the Jewish people in the time of Moses and subsequently through the various Prophets. Punishments meted out to the Jewish People over the millenia are akin to punishments given by parents to their kids - they express varying levels of displeasure, and seek to change behavior. But your children are still and always your children even if they misbehave, and one could say the same of G-d's relationship with the Jews.
Point of Order: since I do not believe in the validity or Divinity of the Christian Bible, and since your faith as a Christian is heavily dependent upon the Hebrew Bible (your "Old Testament," in which Jesus believed), I think that it is only sensible to debate/discuss/explore theological concepts with the use of Hebrew Bible/Old Testament text.