Regardless of your political beliefs and opinion, this is best described as an absolute aberration with respect to the normal democratic process of the U.K.
I'll give you one clue. It's extremely rare to hold a referendum of such huge consequence.
Heck, I'll give you a second clue. It's even more rare for politicians to then behave as if the result of a non-binding referendum is binding.
I could enumerate for you the remaining peculiarities, but if you're curious you'll find plenty for yourself.
I do understand that people often like to point to simple cases like this and say "That's Democracy!", inevitably those people don't have a great understanding of the meaning.
This referendum was more or less a confidence vote on the government. If British democracy were functioning properly, the government would have resigned, and the people would have had a chance to elect pro-brexit representatives.
But Britain adopted fixed election dates, copying the American electoral system. And referendums, for that matter, aren't very parliamentary.