All persons subscribing to the City's supplemental ambulance service shall be deemed to have agreed to an assignment to the City of all their rights and entitlement to the benefits of any insurance attributable to ambulance service provided by the City pursuant to this chapter. Similarly, all residents of the City subject to the provisions of this chapter shall be obligated to pay for ambulance service a sum equivalent to their insurance coverage. Any person receiving insurance benefits who fails to pay them to the City shall be liable for the same. (1991 Code § 11-23)