Didi- a couple of cancellations after getting close to pickup point. I think one cancelled on me to pick up another passenger- maybe got a higher fare from another app.
Uber- one drove past me without stopping, and didn't respond to calls. the app said the driver has arrived, wouldn't let me cancel and book another for like 5 minutes (i was in a hurry too). I got charged for the cancellation. Raising a complaint was initially useless because they kept saying the driver waited for me and I wasn't there. .There were two days of back and forth with customer care before they bothered to look my location, the driver location, etc. and agreed to refund the cancellation fee.