Bought a used car with wrong mileage on odometer

Hello,

I bought a used Toyota Auris from a trader. The mileage on the Auto trader advert description stated 44,000 miles. After buying the car and bringing it home I noticed that the odometer read 21,000 miles. I phoned the trader after noticing this and he said that the odometer was changed at around 25,000 miles which reset the mileage and that's why it's showing a lower mileage.

There was no mention of this in the advert or when I went to collect the car. I know I should have checked this but I missed it because I was busy checking other details.

Do I have any grounds to reject the car?

Thanks