Car wrongfully sold as 'Spares and Repairs' - England

Back in May this year my girlfriend was looking for a new car. She found a listing on auto-trader for a local small garage (about 10 cars) for a 2014 Peugeot 208 on about 55k miles listed in good condition. She called up and booked a test drive where she drove it as well as her step dad. The car had a full service history and my girlfriend paid for a premium background check to check the mileage was correct. She decided to buy the car for £2.9k.

About 2 weeks ago we were doing the food shop in Aldi and the car was having lots of issues, flashing engine light, getting no revs and overheating a lot. We contacted a local garage and they towed it the next day and diagnosed it with a catastrophic internal engine damage. They advised testing and stripping the engine and repairing the car would exceed the car’s value.

After doing some digging online i found that under the Consumer Rights Act (CRA) 2015, if a car purchased from a trader has engine failure within the first six months, the seller must prove the fault wasn't present at purchase. We informed the seller of this multiple times over email and heard no response until my girlfriend finally text them and they came back asking for a receipt if what the garage said. After chasing them again they rang my girlfriend saying they would diagnose the engine FOC as long as we paid for the car to be towed to their garage.

I once again found that the CRA states that in their attempt to repair it is their responsibility to move the car to wherever the repair takes place. Once we explain this they called my girlfriend again (Which she recorded this time) stating that the car was sold as spares and repairs and this voids all of our rights. My girlfriend nor her step dad were ever told of any issues when viewing, test driving or purchasing the car. My girlfriend is also adamant that the auto-trader listing has no mention of the above and was listed as good condition (We have requested the listing from auto-trader).

However, it does say hand written in quite small writing on the receipt that the car is sold as spares and repairs and it has my girlfriends signature on it. We think as they let us test drive the car and drive away from the premise this car have deceitfully been sold as spares and repairs.

We have raised a case with the Motor ombudsmen however, this could take over 6 months for a response. Do we have a any ground to stand on? All help is appreciated.