Prior to going to the Ombudsman as mentined above, it may be worth giving citizens advice a call for some advice and if they can help, making it crystal clear you lodged a complaint under CR2015 within the first 30days of taking delivery. Explain eveything that has gone on, along with the dealers attitude “its tuff if it not as good and we are refunding”
They may tell you go straight to the motor ombudsman or offer to help initially prior to taking it further.
Citizens Advice England
Telephone: 0808 223 1133