I'm sorry to hear your refund amount changed so drastically in the final steps of filing. I can assure you that TurboTax didn't take the money, and that it wasn't a technical difficulty that caused your refund to change.
There are a variety of reasons that your refund can change as you go through the process, but I can't see your tax files so I don't have an explanation for you.
Federal IRS recorded retention laws involving anything to do with tax information must be kept for a minimum of 3 years by any tax service. It is in the Federal requirements for e-file providers.