To be denied your planned desires provokes an overreaction.
We move through life assuming our accommodations, requests, and pleas will be met with reciprocity, or at least entertained. While this is a conceit, it is also a mainstay of civilization.
While being spurned smacks of petty boundary setting, if not outright malice, there is no justification for our rage as our mind spins up destructive scenarios: We are owed nothing and in turn owe them nothing.
Their boundary established the relationship: you are free from a relationship or politeness. For this clarity, we should thank them.