(a) An order not to release security, if issued in writing, shall be served on the agent of depository, and copies thereof shall be served on the depository and on each treasurer, who, according to the latest reports filed with the Administrator, has a local agency deposit in such depository; provided, however, that any failure to effect service on any such treasurer shall not invalidate any action taken pursuant to this Article.

(b) An order not to release security, if issued orally, shall be communicated to the agent of depository either in person or by telephone. The writing confirming such order shall be served in the manner provided in Subdivision (a) of this Section for the service of an order not to release security issued in writing; provided, however, that any failure to effect service on any treasurer shall not invalidate any action take pursuant to this Article.