Reserved a cab the night before to pick up at 7:00am to get me to my GRE. It was 7:15 and I hadn't heard anything so I called. They were very rude on the phone and told me that it would be another 20 minutes before anyone could get to me, which would be 35 minutes after I reserved it. All they said was "we are pretty busy". Ended up canceling the cab and using an uber, which I would have done originally if I had thought ubers would be out that early.