My question involves business law in the state of: Florida

We purchased a used car through a dealership and was told the financing was approved. We provided $6000 down (2k down and 4k to pay off a used car) - I went in there with my girlfriend who lives with me for 3 years and test drove the vehicle. Well it seems the dealership only used my girlfriend's credit along with my moms credit as a co-signer, and did not even put me on there per my request. Well we have had the vehicle for 3 weeks and the finance company made a welcome call to my girlfriend. She told them I was driving the vehicle (she is paying for it) and they told us it was a straw deal. The dealership knew we would both be driving the car and at no point did they tell us that I wasn't allowed to drive the vehicle per the finance companies rules. I also looked over the paperwork and we didn't sign anything saying she was the only driver. They now (25 days later) want the car back. They said the trade in car is gone, I have a feeling they are going to only try to give me back my 2000 and not my $6000. Do I have any options here? We never lied to anyone and we are being called liars by the finance company and being accused of a straw deal.

I am looking for advice on what to do.