Problems with the city and classification of house

[Jeremy Moore]

Hey all,

We are currently dealing with the City of Phoenix about the classification of a property that we purchased as a single family home with an attached casita. The City is insisting that it is a multi-family dwelling and is charging us double for trash services and 4x - 7x sewer services. We know that it was appraised with a Specific Zoning Classification: R1-6 - "Zoning Description: Single Family Residence (Density Range of 5 To 5.5 or 6.5 w/Bonus)" and that the County Assessor recognizes it as such.
Public Works has sent out 5 different inspectors who have given different reasons why it is multi-family (e.g. the casita has an exterior door; the casita has a sink; we could feasibly rent it out and the renter would need their own trash service [we have only one large trash bin in the alley shared by multiple residences]). We do not think any of these are valid. They have offered to charge us for a single trash service if we will sign a document stating that the dwelling is multi-family. We believe this would be a very unwise move on our part.
This has become exceedingly frustrating and we are reaching out to you both as industry professionals for help. I think that the next step might be to either contact our Councilman (Sal DiCiccio) or pursue legal counsel.
Anyone have any resources to which you can point us to help resolve this issue? We would be very grateful for any information you all can offer.