The monthly retirement allowance or pension originally granted to any retirant and the pension or survivorship benefit originally granted to any beneficiary shall be adjusted in accordance with the provisions of this act.
Pension increases shall not be paid to retirants or beneficiaries who are not receiving their regular, full, monthly retirement allowances, pensions or survivorship benefits. The adjustment granted under the provisions of this act shall be effective only on the first day of a month, shall be paid in monthly installments, and shall not be decreased, increased, revoked or repealed except as otherwise provided in this act. No increase shall be due to a retirant or his beneficiary unless it constitutes a payment for an entire month.
N.J.S. § 43:13-22.70