(a) There shall be no liability upon the seller for erroneously collecting the tax hereby imposed and levied or for erroneously failing to bill for such tax as a result of a good faith mistake on the part of the seller. When any purchaser contends that such tax is not owed by such purchaser on the ground that the public utility service was not purchased, used, or consumed within the corporate limits of the city, the seller shall refer the question to the City Treasurer, 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 the City Treasurer. Any and all claims for refunds of any such tax shall be presented to this city and not to the seller.
(b) The City Treasurer shall have authority to promulgate and enforce reasonable rules and regulations necessary for the administration and enforcement of this article.