Unreliable and dishonest dealership

They advertised a car on Autotrader, and I liked the car and they say there is a money that is needed to be paid up front to secure the deal of which I paid it. I app**** for financing through them after I had calculated for myself how much the installment will be without the balloon payment.

They then told me that they secured financing and told this huge installment above the one I calculated, worse it has the balloon payment. I asked for the breakdown of the total amount they app**** for a loan and they refused to provide me with it. I told them to cancel the deal and pay back my money and they said they will do. I followed up on the proof of payment with no success and I still haven't received my money.