Each and every seller shall keep and maintain complete records showing all purchases of public utility service within the corporate limits of this municipality, which records shall show the charge made against each purchaser, the dates such public utility service was furnished, the date of payment therefor, and the amount of tax imposed hereunder, and such records shall be kept for a least two years, during which period they may be inspected by the duly authorized agents of this municipality, at reasonable times, and duly authorized agents of this municipality shall have the right, power and authority to make at the expense of this municipality, such transcripts thereof during such times as they may desire.