Two bookings, no taxi showed up! Almost missed my flight

I booked two times via Taxi2airport on the same day, for the pickup and for when arriving at my destination. Both taxis didn't show up! On purposely I booked a van in advance for my bicycle. For the pickup, after one hour waiting and multiple calls to the helpdesk, they mentioned they can't reach the driver, no other vans are available, and I should arrange my own transport. This gave a huge stress and I almost missed my flight. On arrival in another country, they cancelled the booking while I was on the flight. So also there, I had to arrange my own transport. Very unreliable service!