Credit Acceptance Financed my 9000 dollar car to 15000 and took my down payment Southfield Michigan

I wanted to purchase a vehicle from a dealer, they financed my car through credit acceptance. The price on the vehicle after negotiation was $9000 the dealer said I was approved for financing as long as I could put some money down, I put $1100 down, so the price I paid was $7900. The amount they financed was over $15,000. Now my situation has changed and I'm driving a lot farther to get to work, so i was looking for a newer more fuel efficent vehicle only to find out that to get another vehice I need to come up with over $5000 down to compensate for what they did.