A creditor may not directly or indirectly take or receive from a debtor an obligation that constitutes or contains an assignment of wages or other earnings unless
(1) the assignment by its own terms is revocable at the will of the debtor;
(2) the assignment is a payroll deduction plan, commencing at the time of the transaction, in which the debtor authorized a series of wage deductions as a method of making each payment; or
(3) the assignment applies only to wages or other earnings already earned at the time of the assignment.