Taxi Card using mini-cabs

I'm sure that some of you may be entitled to use a taxi card for subsidised journeys by cab, usually a London black cab. But some times they use mini cabs. Now, I have no issue with this normally, sometimes it can be better value, (when stuck in traffic for example) but some of the offices they use leave a lot to be desired.

There is one in particular that I have in mind. They're terrible. Recent issues include a detour around the back of the Whittington hospital on the way to the UCH in Euston road. (Subsequently late for that appointment) Waiting for me outside my house and arguing with me on the phone that he was there when he was in fact outside a house in the next road. (Again it made me late) and only last week they were to pick me up from the Whittington to bring me home. I sat outside and watched the many cabs come and go but mine didn't turn up. I watched one cab pull up on the other side of the road for a few minutes then drive off. He returned five minutes later and parked in the same place before driving off again. Fifteen minutes later he was back, waited for a couple of minutes then off again. By now it was nearly an hour since I'd called so I called again to find out where my cab was. I was asked if I'd been contacted by the driver in any way, the answer being no. I was told he'd been despatched within minutes of my first call and should have been there by now. They checked and told me he'd be there within a few minutes. And there he was, parked on the other side of the road and not in the hospital pick-up area. I knew it was him because this time he phoned me. I wasn't happy about having to go across the road and he agreed to drive into the pick-up area for me. 

And guess who it was? That same cab that I'd been watching driving around nearly an hour earlier. Did he think I would recognise him as the cab that I'd booked? Out of all the other cabs that were pulling in?

I've tried reporting it to Com Cabs but I don't think they take any notice. I'm beginning to think that there's some sort of incentive there to use this particular cab company even though there are offices that they use that are a lot nearer. As soon as I hear the name "Station Cars", who are based in Wood Green, I get a feeling of "Oh no, not them" and am not surprised by their shoddy service any more.

Has any one else had any dealings of this sort using their taxi card?