Seriously, that sort of crap happens all too often at the lower end of the scale. It's one reason why you want to get moving up to better gigs.
But at least it's the sort of thing that gives you "experience". A few such gigs can be a good thing, as long as they don't just make you give up. They teach you to think on your feet, they teach you to be prepared, they teach you what can go wrong, they teach you to be wary of promising too much (eg. offering a recording from the desk), etc. But you don't want too many of them!