Is the torment of disbelievers and atheists in Hell, "abiding therein for ages," perpetual, and does this contradict God's justice and mercy, or does it continue for ages known to God, and what is their fate thereafter, and why is this not mentioned in the Qur’an or Sunnah?

The Sunni consensus is that Hellfire is real, an abode of torment that will not perish, nor will its inhabitants perish, endlessly. Disbelievers will abide therein eternally, and none shall exit it save the disobedient monotheists. The evidence from the Qur’an and Sunnah (definition) has converged on the eternity of Hellfire and the perpetual abiding of disbelievers therein, and that their destiny after eons is the continuation of torment, because these eons are unending and ceaseless. This is consistent with Allah’s justice and wisdom.