I don't practice in the federal court system, but since no one else has taken a crack at this, here's my best guess. I can certainly understand why you would think that the restitution amount owed under your judgment was only for $12,000 (or $12,100?), and that if you've now paid that, you should be off the hook. Unfortunately, that amount and the restitution amount don't have anything to do with each other. The $12,000 isn't for restitution (money which the court orders you to pay to reimburse the victim for its losses). The $12,000 is just the fine that you owe the government. What I don't understand about this is that at least in a state judgment, you would be ordered not only to pay off the fine at $200 per month, but would also be ordered to pay restitution, probably at some horrendous amount per month, though arguably that might depend upon your ability to pay it. Did the government seize any of your assets as proceeds of the fraud? Or did the complainant (the bank or maybe the FDIC) file a civil suit and end up getting assets to satisfy the civil judgement? If so, conceivably some of the restitution amount may have been satisfied that way. Anything left over, though, you'd still be at least potentially responsible for both criminally and civilly. I'd talk to the attorney who represented you originally on your criminal case if you can, and if you for some reason can't, find another criminal defense attorney who practices in federal court and ask them to look at your judgment and if needed, look info what's going on with the remaining restitution. Personally, I don't really understand why the federal prosecutor or probation/parole officer would have just let that much restitution go for the five years you say you've been released, unless the judge made a finding that you were unable to pay the restitution (and I'd think that finding would be subject to a periodic review to make sure your financial situation hadn't changed).
I cannot provide any further presumption regarding this situation without seeing the judgement and your plea papers, but I suggest you contact the original attorney that helped you and ask them for their guidance. If you were sentenced to time and an extended probation you had to have an attorney, so that person is in the best position to assist you in understanding the terms you agreed to.
Contact your original attorney or try to get an explanation from the probation. There may be a legal clinic at one of the local law schools that can help you.
This is intended as only general legal advice. Feel to visit my website, www.austincriminaldefenseattorney.com for my blog on crime and punishment in Texas You may also email me through my site.