Used car order, misleading advert in England

Hey all!

I'll try and keep this short so that it's not a TL:DR post. Basically, found a Kia Optima online from a Skoda main dealer (approved used). Rang up, placed a deposit (have owned one of these cars before), and after I said over the phone I'd be happy with the purchase, I was asked to bank transfer the balance... which I did, to the tune of £16495 (silly I know).

However, I have gone to view this car today for the first time in person, with a view to signing sales documentation for the order etc & to check all was in order with it.

However, first things first... it has an engine management light on, which they are insisting is because the car needs a service but I have had this confirmed from Kia that an engine management light would not show for this reason.

BUT... the biggest reason....

I ran a HPI check tonight, and it has come back as previously used as a taxi. This wasn't declared on the advert, be it auto trader, or their own website. I personally feel this has been a classic misrepresentation.

Does anybody know where I stand in terms of cancelling the order and if they will give me my 16k back?

Ive worked really hard to get these funds aside (as I struggle to get finance), and want to know where I stand in terms of cancelling the order. Can they force me to take the car?

The entire process was done over the phone, and from home up until today... so no funds have ever been transferred whilst seeing them in person so I am hoping I am covered by several regulations, mainly distance selling etc.

Any advice is greatly appreciated, as I am incredibly worried that they're going to force me to take the car at the threat of not returning over £16k of my money etc. It is genuinely making me feel to my stomach that I've lost 16k

Many thanks all!