My $500 Down Payment Was Rejected By CarHop Auto Sales & Finance

I tried to get financing from a regular car dealership, but they turned me down because my credit was so bad.These guys said they're flexible and accepted my $500 down payment. At first glance, everything seemed to be going smoothly, and very understanding of my situation. But the vendor suddenly pulled out of the agreement, barely two days after we made it. First they started delaying the process then, I found noone in charge to discuss the issues. The seller's apparent reluctance to resolve the matter and rushed decision to reimburse my down payment is not very trustworhy. I'm not just writing here to complain but also would like to hear from someone who has been through this before and how they handled it, please comment.