Out of interest, what 10 year old model has pre-conditioning as standard even in the base trim?
In regards to the actual problem: your option is to reject the car and hope that Motability doesn’t charge you an early termination fee.
As much as it sucks, the fault certainly doesn’t lie with the manufacturer (the option was removed almost a year ago), plenty of notice for you to keep an eye on the progress/info on the car and potentially notice the problem. The dealership of course didn’t do its job properly either, but in the end you signed off on the car.
It does sound somewhat like some sort of VW (or VAG) PHEV/EV that you got there, you could potentially get lucky and check if it got added to the in-car shop, as there’s no actual “specific hardware” for preconditioning necessary, it’s just computerstuff. Much like the optional voice control in the car that we have on order (Golf GTE), you can order that through the cars infotainment, the required hardware is already on board.
In the end, i don’t think you’ll get much out of the dealership either. They’re not legally required to upgrade you for free – they might give you a discount if you order your next car through them after you rejected/terminated it, but it’s not a requirement either.
I will say that i’m always rather sceptical if someone asks for help/opinions etc and omits basic information like car model, year, trim level, date of order etc. Based on that, it’s not entirely clear if the information about said option was readily available at the time.
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.