The provisions of the Ad Valorem Tax Code¹ relating to the duties of various officials, and the time within which such duties shall be performed, are hereby declared to be mandatory; and the failure of any such official, board or commission, to perform the duties prescribed herein, within the time specified, shall subject them to removal from office for neglect of duty; and they shall receive no remuneration, compensation or salary for their services, after the time herein fixed for the performance of such duties and until the same shall have been completed or performed. Each of them shall also be subject to a penalty of Five Dollars ($5.00) per day for each day's delay for such neglect or failure; and it shall be the duty of the district attorney as to county officers, and the Attorney General as to state officers, to institute proper action to collect any such penalty; provided, that the validity of any assessment or levy shall not be affected because of any insufficiency, informality or delay in the performance of any duty imposed upon any official, board or commission.