One of the best kept secrets in the military is that you have the right to petition your commanding officer (CO) directly for help. Article 138, UCMJ, can be one of the most powerful and effective tools for seeking redress from your superiors in a timely manner.
Often times people in the military are tricked, coerced, or misinformed into believing that they must sign certain documents such as extensions, reenlistments, job reclassifications, or an agreement to spend a remaining service obligation in an active guard unit. Most of the time such agreements are voluntary, but because of command pressure, the person signing them thinks they have no choice. The command creates the impression that the person must sign and then, after the fact, tells the person that they voluntarily agreed. However, if the command has the authority to require the military member to take an action, they can just cut an order. Being asked to sign normally indicates that the action is voluntary.