If any change or error in records results in a member or beneficiary receiving from the retirement system more or less than he would have been entitled to receive had the records been correct, then on discovery of the error, the board of trustees shall correct it and, so far as practicable, adjust the payments in such a manner that the actuarial equivalent of the benefit to which he was correctly entitled shall be paid.
N.J.S. § 18A:66-63