>>534165858
since i can't make a good judgement of what pressure/force you exerted on it, nor do i know where that fracture is, we can only safely say that the object was made faulty and that the plastic experienced "Materialermüdung" (material fatigue) which simply occurs when the object is stressed within its limits one too many time and any rigid material having some point of wear, abrasion or elastic maximum exceeded in so that the faults start to show.
in terms of elasticity, a plastic object still exhibits SOME elasticity, however with continued stress the elasticity decreases until the same stress causes the object to crack/snap/break.
i would call in your warrant.