If a franchise company goes out of business is the franchisee responsible for the debt of that store?

I am the office manager for a small company in Colorado Springs and I have been contacting a man that used to own American Engine Installations (an old customer) for the last year in regards to a balance he owes on the account. The company went out of business some time back and the gentleman claims we cannot contact him regarding that account since it was a franchise. I am unfamiliar with how exactly that works. He was the owner of that specific location and was the one that signed the contract stating that he was the owner. He says that they went bankrupt but is unwilling to supply the proper paperwork. Is he still liable since he was the owner and signer of the contract? I would love to get this off my desk. Thanks for your answers in advance!