There is not a hint in the Torah of G-d reacting to Israel's violation of Torah by replacing it with something else.
Jer 31:31 "The time is coming," declares the Lord, "when I will make a new covenant with the house of Israel and with the house of Judah.
Jer 31:32 It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, because they broke my covenant, though I was a husband to [fn] them, [fn]" declares the Lord.
Jer 31:33 "This is the covenant I will make with the house of Israel after that time," declares the Lord. "I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people.
Jer 31:34 No longer will a man teach his neighbor, or a man his brother, saying, 'Know the Lord,' because they will all know me, from the least of them to the greatest," declares the Lord. "For I will forgive their wickedness and will remember their sins no more."
Sounds great. Too bad it didn't happen two thousand years ago.
I said there is no hint in the Torah. The Torah is the Supreme Revelation. No prophet can overthrow the Torah. Any prophet who did so would have been a false prophet and his prophecy would certainly not have been canonized by the Men of the Great Assembly who compiled the canonical books of the Prophets and Writings. In order for the Torah to be replaced by something else, the Torah itself (Genesis/Exodus/Leviticus/Numbers/Deuteronomy) must authorize it.
Also, you are assuming (based on your chr*stian presuppositions) that the "new covenant" Jeremiah prophesied is chr*stianity. This is what chr*stianity claims, and this is what you have always believed, but in order to believe this is a prophecy of chr*stianity, one must already believe in chr*stianity.
There are numerous covenants in the Hebrew Bible, but only one Torah. G-d made a covenant with Israel at Sinai and another in Mo'av just before Israel crossed the Jordan--two covenants, but the exact same Torah.
Jeremiah may have very well been predicting the days of `Ezra', when the people made another covenant with G-d and put away their foreign wives and idols. Or it may refer to the Messianic era when the Davidic King rules from Jerusalem and all mankind has rejected false "gxds" and embraced HaShem. But in neither case is the Torah replaced by something else. However many covenants, there is only one Torah.