Why does it say that there will be no Kaparah via Zevach and Minchah?
Rabah (Yevamos 105a): There will be no Kaparah via Zevach and Minchah, but there can be Kaparah via Torah.
Radak, based on Abaye (Yevamos 105a): There will be no Kaparah via Zevach and Minchah, but there can be Kaparah via Chesed (Rosh Hashanah 18a - and Torah).
Radak, based on Yerushalmi Rosh Hashanah 13a: There will be no Kaparah via Zevach and Minchah, but there can be Kaparah via Tefilah.
Radak: Because they sinned via Zevach and Minchah, they cannot atone through them.
Malbim: What they sinned via Zevach and Minchah, there will never be Kaparah for it. For other sins there can be Kaparah via Teshuvah, for the Navi did not warn about these.