Scotland - purchased a faulty car from Motorpoint

I purchased a car from Motorpoint in Glasgow which I collected on December 22nd 2025. That evening I got an amber engine management light on which I reported to them on the 23rd. Due to the Christmas break my initial 10 days expired so they passed me onto the warranty company to deal with the fault, the warranty running until March 2026.

The warranty company sent me to a local garage which was heavily backlogged and couldn't actually inspect the car until 3rd February 2026 where they diagnosed it as a fault in the engine purge system, tied to an EVAP valve, car can be driven but due to the engine warning light would not pass an MOT. Following this there was a few delays until the finally prdered the parts in May 2026, now outwith the warranty period, with the repair being completed on August 6th.

On the evening of the 6th the engine warning light came back on, the same garage has diagnosed it as still a fault in the purge system but now tied to the EVAP canister. The warranty company is refusing to have any dealings with it now, stating that the warranty expired in March and they are treating this as a brand new fault. Motorpoint says the same and have sent me back to the warranty company.

I would like some assistance on where I stand on this. I don't understand how I can be sold a faulty car which an MOT (which is due next month) would state was not ok to drive and to essentially get told by the original dealer "tough luck, deal with it yourself".