Ya, at first look, that deduction appears to be not in order. You may try your luck at the Labour Office. Hope they can use the power under Section 69B of the Employment Act to help you as it involves salary matters.
"69B. Additional powers of Director-General to inquire into complaints.
(1) Notwithstanding the provision of this Act, the powers of the Director-General under section 69(1)(a) shall extend to employees whose wages per month exceed 1,500.00 ringgit but does not exceed 5000.00 ringgit...."