(a) There shall be no liability upon the seller for erroneously collecting the tax imposed and levied by this article or for erroneously failing to bill for such tax as a result of good faith mistake on the part of the seller. When any purchaser contends that such tax is not owned by such purchaser on the ground that the public utility service was not purchased, used or consumed within the City, the seller shall refer the question to the official of the City charged with the responsiblity of collecting taxes due to the City, and such seller shall thereafter collect or refrain from collecting such tax from such purchaser for such public utility service as instructed in writing to do by such officials of the City. Any and all claims for refunds of any such tax shall be presented to the City and not to the seller.
(b) The official of the City charged with the responsibility of collecting taxes due the City shall have the authority to promulgate and enforce reasonable rules and regulations necessary for the administration and enforcement of this article.