How can the two noble verses: {And they will not exit the Fire} and {Then indeed, their return will be to Hellfire} be reconciled, given that one negates exiting the Fire while the other affirms exiting then returning to it?

The first verse affirms the eternity of disbelievers in Hellfire and their never exiting it, and this is the view of the majority of the Sunnis. As for the second verse, the meaning of "their return" in it is a transition from one state to another within Hellfire by way of metaphor, not an exit from it and then a return to it. Disbelievers do not leave Hell when they consume zaqqūm and drink ḥamīm; rather, this is an additional torment within Hell, or it is their transition between its levels and places of torment within it. Based on this, there is no contradiction between the two verses.