Fi Morgan

I've recieved a tax bill which i believe is incorrect due to a change in company vehicle from lease car to salary sacrafice and also Diesel to fully electric. Can anyone advise how to answer the question "How much did you pay before tax, towards the car?"? i.e. is this per month, per year, over the course of the 4 year contract? Do i take away the cash allowance provided by my company. For example if i pay £700 and the company give me a cash allocance of £500. Do i enter £700 or £200. Hope someone can help please!