During the continued compliance with the terms of this chapter by the owner of any telephone exchange, the charge levied is and continues to be in lieu of all concessions, charges, excise, franchise, license, privilege and permit fees or taxes or assessments except ad valorem taxes. However, this provision and chapter is not intended to extinguish or abrogate any existing arrangement whereby the city is permitted to use underground conduit, duct space or pole contacts of the company for the fire alarm and police call systems of the city. (2000 Code § 7-503)