Is it legal for a pawn company to refuse my car for the money that was due if I have a title pawn on my car and I filed chapter 7?

Probably not. But they may want to turn it over to the Trustee, so that they won't be caught in the middle if the Trustee is entitled to it. Consult your lawyer, and if you have not yet retained an experienced bankruptcy lawyer, this would be a good time to do so. It's almost always worth the investment.

I am trying to figure out what you mean by refuse my car. I think you mean refuse to release the title to or possession of the car. While the pawn shop cannot sue you to collect this debt, they can keep title to the car until you pay what you owe and they can even repo the car if they do not already have possession of the vehicle. Chapter 7 discharges your obligation to pay, but when you have a title loan, the car is also on the hook for paying this debt, and the car did not receive a chapter 7 discharge.

The pawn shop is required to live up to the deal on the contract.