(viii)if the amount withdrawn exceeds the actual cost of the purchase or construction of the house and/or site, or if the amount is not utilised for the purpose for which it is withdrawn, the excess or the whole amount, as the case may be, shall be refunded to the trustees forthwith in one lump sum together with interest from the month of such withdrawal at the rate prescribed in sub-rule (4) of rule 71. The amount refunded shall be credited to the employee's account in the provident fund.