Complain to your municipal government.
This is really going to depend on where you live - around here, lobbying groups for taxi companies and their drivers forestalled any attempts at legislated change for over a decade before Uber stepped in, quickly picking up market share due to its reliability. It used to be that even if you called to schedule a pickup (in an hour!) there was only a 30-40% chance a taxi would actually show up. I remember the days of being unable to get home via taxi at night without offering a 100% tip in advance all too vividly and have no desire whatsoever to return to that.
I'm not saying Uber is the best answer here - clearly, the new model comes with its own share of problems - but the previous monopoly (taxis) really screwed themselves out of a future with their own behavior. There was a hotline to call to report problems, but absolutely zero accountability for the drivers at the end of the day. The situation has since improved, but generally falls along the lines of 'too little, too late'.