Airport Taxi Transfer nearly three hours late - missing flight

Anyone out there had any experience with Transfers-Germany.de not turning up in time. I booked a taxi transfer to and from Memmingen Airport to Berwang.
They subcontracted it to local taxi firm Taxi Karacan.
All fine with outward, but on pick up the driver turned up 2hours 50 mins late.
We had left four hours to get the 100km to the airport. But it was too late to make the flight.
Driver initial rang to say he would be one hour late which was ok. Claiming it took him six hours to travel 100km. It was a Saturday, but neither the weather report, radio traffic reports or the live cctv cameras showed that much delay. Anyway to prove online backdated to Dec 27th the delays on E523 Memmingen to Berwang were not that long.
Transfers-Germany.de so far claiming it was just traffic delay so an exclusion in their terms and conditions.
Nightmare cos we were stuck in a tiny village and no taxis available.
We had to book alternative flight home from Innsbruk. Cost me £1000.
Anyone with experience here. The taxi firms is in Germany. Transfers-germany.de office basked in Innsbruk but parent company based in Croatia.So my next step is the clivil legal case.

You could try bringing it up with your credit card company but guessing easiest way is to claim on your travel insurance