Do automobile loan approvals expire?

I got approved for a loan on Aug 21 and took delivery of a car on Aug 22. It is now 19 days since my loan was approved and the bank still has no record of my account. They said there was a problem with the finance rate on the contract, should’ve been lower (which is good!), and that they sent it back to the dealer for me to resign. My questions is this – I do not have perfect credit but I have never been late with a car payment. I got approved for the loan because of my income at the time. I have since changed jobs and am making less but am more than capable of making the payments (my fiancee who was not on the loan makes enough and I really don’t need a job). Do loan approvals expire? I will not be able to get reapproved at this point (and can’t add my fiancee because he has no credit – we already tried). I actually already have the title for the vehicle but no loan statement! What would happen in this case?
They have to recontract because the contract states 7.9% and it should be 3.9% (paying your car loan on time really pays off btw if you have bad credit – you can still get great deals on new cars!). I just got a call today that I can come in and resign. And I can’t give them the car back (or rather won’t) – they sold my trade-in, without paying it off which, btw, is against the law in WI but because they are part of a group of dealers the state was willing to look past. What are laws for if these crooks don’t follow them? They sold it 11 days after I traded it in and didn’t pay it off for 15 days after I traded it in (after I called the lender to let them know what they did). WI law states that you cannot sell a car without a title, which they didn’t have because it was a lease and the lease co holds the title.