I went to a dealership 2wks ago. I have bad credit, high debt to income ratio and on debt management. I put 10

I put 1000 down and now they called me 2 weeks later asking for another 500.00 What the heck? Why are they asking me for more down the car is about 9000 dollars. I'm seriously going to just drop off the car and be like I can't afford to give another 500 to you guys give me back my money that I put down.
The financing wan't finalized, they were searching to see if someone would finance me.