All ambulance fees and charges are due upon presentation of a statement by the City, and shall be promptly paid by the user, his legal guardian, or in case of death of user, by his user's estate. After a reasonable time following presentation of the statement by the City, the City may cause a suit to be brought for the collection of any fees or charges for ambulance services. The City Council, by resolution and at its discretion and under special circumstances, may waive fees as set forth in this Chapter. (1985 Code §3-6.06)