A fee of $300 for a zoning text amendment and a like fee for a Zoning Map amendment shall be paid to the Town at the time the application is filed. Charges will include the costs of the Town's employees and consultants. When the application is concluded by the Town Council, the charges will be assessed, and if less than the fee imposed, a refund will be given to the applicant, and if greater, the applicant will be billed for the difference. Fifteen percent will be added to the total charges for the Town's administrative costs and overhead. The rates for charges shall be established from time to time by resolution of the Town Council. Charges will be billed monthly if in excess of the fee imposed as set forth above. If any charges are not paid within 60 days of billing, the Town will withhold further review, approvals and/or issuance of any required permits until paid in full, together with interest at the rate of 1% per month or fraction thereof from the date of billing to the date of payment.