Yup, agree with dave, if you leave it too long, the car will be locked for production, and will make it difficult for any adjustments to be made, and harder to reclaim the deposit. If he won’t budge, then just say, reluctantly, you will go elsewhere, and you expect them to refund your deposit, within 7 days, At this stage, follow up by an email, try and copy in the sales manager. Include links to marshalls offer in the email, make it easy.