(a) The secret payment or allowance of rebates, refunds, commissions, or unearned discounts is an unfair trade practice, whether in the form of money or otherwise or secretly extending to certain purchasers special services or privileges not extended to all purchasers purchasing upon like terms and conditions to the injury of a competitor and where the payment or allowance tends to destroy competition.
(b) Any person, firm, partnership, corporation, or association resorting to such trade practice shall be guilty of a Class A misdemeanor.