Happens ALL THE TIME in Hong Kong. The worst case so far, I've had a driver call me as soon as I submitted the pick up request, hung up the phone immediately as I mentioned where I was going, then stayed without moving for the next 90 minutes, without cancelling (I took a cab long before that). Similar, though less intense experience happened to me on about 20% of the rides, every time I have to go through the claim process to (automatically) get my money back.

Infuriating, I really wish there was viable alternative to Uber in HK, but taxi drivers are a lot worse (disgusting, rude, very frequently refuse a hire...).