If you have not been paid money which you were due for work (or sales) you did (or made), then you may sue your employer, such as in small claims court, to recover the money. A worker must be paid everything due him or her pursuant to the terms of employment. A critical issue, therefore, will be the terms under which you earned your commission: some companies, for example, require that an employee still be employed as of when commissions are paid to receive them, and, if so, that is legal. Therefore, you can enforce whatever the terms were under which you earned your commissions, if such terms were favorable to you in this situation.