(a) A director, officer, or employee of a state bank may not knowingly, wilfully, and persistently overdraw the director's, officer's, or employee's account or permit a customer to do so.
(b) An overdraft of more than 30 days' standing may not be allowed as an asset of the bank.
(c) The provisions of this section do not apply to an approved overdraft created under a check guaranty plan or other similar revolving credit plan.