Speak with Motability, telling them the fault has reappeared and you have lost faith in the car and no long trust it. Motability are understanding in situations like this and will allow you to terminate your contract and look for another vehicle.
As other have said, you will loose out on any optional extra’s you paid for and will be refunded your AP on a pro rata basis.
As a side note, options, whether that be paint or other factory fitted options aren’t necessarialy the best option imo.