Woofy
you could argue the car doesn’t suit you due to your current health, effecting your finances, I’d leave the running costs out for now as they can say you should have done your homework on mpg before ordering.
Motability only charge a possible maximum of £250, but are likely to wave that if you make it clear your financial situation and you can change I believe three times in 7 years? From memory which is a bit hit and miss.
when your feeling up to it order another car, With the lower AP.