Faulty formulation: Because Paradise and Hell are created, they must ultimately cease to exist.
Correct formulation: Createdness alone does not logically require eventual extinction. Allah created Paradise and Hell, and their enduring existence remains dependent upon His will and sustaining power.
Application: It would be wrong to describe a creature as self-subsisting and eternal in the way Allah is. It is also wrong to deny the possibility of its enduring because Allah preserves it. The Creator's beginninglessness and a creature's bestowed permanence are not the same.