By any chance, was it a shell station?
If you google “q3 diesel pump not fitting”, there’s plenty of people having a similar issue – which is the pump nozzle, not your car. Your car’s fitted with a protective device (as was explained) that has to trigger correctly, and that only works with the correct nozzle.
I’d try another petrol station.
If nothing else works, there’s always fuel nozzle adapters – basically a funnel that triggers the flap. Bit of a hassle though, i’d rather just go to a different petrol station.