I made a verbal agreement with my local VW dealer to purchase a used Polo with mats and Autoglym included for free in the negotiation. He offered me £400 for my X reg Ford Fiesta which I told him had dodgy door locks and a rattle in the front offside.

I told him the amount of money I wanted to pay and we agreed a price, shook hands and I paid a £500 deposit.

He asked if I minded how he "cut" the deal on paper and I said it was fine as long as I paid him the £9k for the car plus my part ex. The paperwork came through showing £800 for my part ex and the mats and auto glym as £400 extras I had agreed to purchase. I did not sign this.

Yesterday my car was damaged in an accident that was not my fault so I cannot part exchange it.

As I am still keen to purchase the car I phoned and asked if I could pay the agreed balance plus the £400 part ex value but the dealer has now said that actually he was offered £800 for the car as part ex, so if I want the Polo and can't provide the Fiesta the total due is £9,800 plus the £400 for the mats and Autoglym.

I verbally agreed to £400 part ex and free mats and Autoglym and have not signed the contract which details the £800 part ex and £400 to be paid for the mats.

Where do I stand on this please? Can I get my deposit back or can I hold them to the verbal agreement?