W. Va. Code § 18-7A-14c
(c) Overpayments to the retirement system by an employer. — When mistaken or excess employer contributions or other employer overpayments have been made to the retirement system, the board shall credit the employer with an amount equal to the erroneous overpayment, to be offset against the employer’s future liability for employer contributions to the retirement system. If the employer has no future liability for employer contributions to the retirement system, the retirement board shall refund the erroneous contributions directly to the employer. Earnings or interest shall not be returned, offset or credited to the employer under any of the means used by the retirement board for returning employer overpayments to the retirement system.
(d) Overpayments to the retirement system by an employee. — When mistaken or excess employee contributions or overpayments, have been made to the retirement system, the board shall have sole authority for determining the means of return, offset or credit to or for the benefit of the individual making the mistaken or excess employee contribution of the amounts and may use any means authorized or permitted under the provisions of section 401(a), et seq. of the Internal Revenue Code and guidance issued thereunder applicable to governmental plans. Alternatively, in its full and complete discretion, the board may require the employer employing the individual to pay the individual the amounts as wages, with the retirement board crediting the participating public employer with a corresponding amount to offset against its future contributions to the plan. If the employer has no future liability for employer contributions to the retirement system, the retirement board shall refund said amount directly to the employer: Provided, That the wages paid to the individual shall not be considered compensation for any purposes of this article. Earnings or interest shall not be returned, offset, or credited under any of the means used by the retirement board for returning member overpayments.