Been there done that and this is how it was for me.
Got chucked off Motability end of November 2017 and took the £2,000.
Went to tribunal April 2018 and won.
Tried to rejoin Motability in April 2018 and at this time its been 5 months since compulsory leaving Motability and was told if I rejoin Motability before the 6 month leaving time had expired I would have to repay £1,750 of the £2,000.
Go the go ahead to rejoin with no penality the 4th July 2018 and that’s when I ordered my car and paid nothing of the £2,000 back.
So short of it is if you take the £2,000 and rejoined before 6 months has passed you will have to repay them £1,750 of the £2,000 but after 6 months, nothing.
Just another note worth mentioning is that Motability give you, from memory, upto 5 week grace to return your Motability car and that 5 weeks or however long it is Motability don’t get paid any money from the DWP because your allowance at that time would have been stopped so its a sort of free grace time.
The big crunch comes after you take the £2,000 and your 6 months has passed and you can rejoin with no penalty they want the money for the free gratis time for when you had the car but Motability were not being paid by the DWP. This should not be a problem though because you will be paid all the money that DWP did not pay Motability back into your bank account so you should have the money to cover that, its a “ out of the frying pan into the fire “ situation but you don’t lose anything but just don’t think you’ve hit the jackpot when you see that back payment in your bank.
Of course if you don’t rejoin you don’t pay that money back.