Every seller of utilities service shall keep complete records showing all purchases in the city of such utilities service, which records shall show the price charged upon each purchase, the date thereof and the date of payment therefor. The records shall be kept open for inspection by the city treasurer or any other duly authorized agent of the city during all business hours on all business days, and the city treasurer or any duly authorized agent of the city shall have the right, power and authority to inspect the records and make transcripts thereof during such times as he may desire, provided that the right of inspection shall be exercised, as far as possible, so as to not interfere with the orderly arrangement and conduct of the books and records of the seller.