What would a pilot do if none of the control surfaces are responding?
For example, a pilot flies a medium-sized plane and to make the situation a bit less hectic, they're the only one onboard. Then they make a subtle turn, but nothing moves. They try again, but the plane isn't turning. They then become quite worried and assess the situation, trying if any of the control surfaces are working. To a shocking realization, none of the control surfaces are responding. And luck isn't on their side: when the control surfaces stopped responding, the plane was at a slight descent of about 5 degrees. If they can't figure out what to do soon, they're going to collide with the ground. The pilot can't tell what is causing the problem but assumes that it is something wrong with the control surfaces themselves, not the control linkage between the control surfaces. The pilot can't tell if the control surfaces are frozen, stuck, or broken. And the final take is that the plane isn't going slow enough for the pilot to safely bail out of the plane. They guess that they have at most 8 minutes before they crash.
So what would the pilot do? And if it seems highly unlikely that such an event would ever happen under the given circumstances in the example provided, then imagine a significantly different scenario in which a pilot is in a P-51 Mustang and they've been shot all over (the plane, not the pilot) to the point where nothing is working, likely linkage failure or other damage. What would a Pilot do, especially if they're in a situation where bailing the plane just isn't an option?