They are disorganized, and they make you pay for it.
I used their services to get to the airport several months ago.
I called and made the reservation from my home phone number. I gave them my cell phone number to call me when the cab arrived.
I was waiting downstairs and did not hear from them at all. I eventually found the cab they sent me driving around the neighbourhood. They had been calling my home phone number to let me know the cab arrived.
They charged me an extra $5 for keeping the cab waiting, on top of the flat airport rate. Because they messed up.