Crown Dodge Of Fayetteville Car Dealership Repair Frustration for Crown Dodge of Fayetteville Fayetteville North Carolina

Over the course of the last few weeks I've been trying to get my car serviced so I can pass my NC state Inspection. After some checking, by word of mouth and referrals from auto parts stores; I took my car to a local Midas service station.
After running the diagnostic, I was told that it was a purge solenoid that needed to replaced. Also if after fixing the purge solenoid, if my check engine light continues to stay on then my PCM (car's computer) needed to be reprogrammed. I was not too confident in the info so I found another local shop for a 2nd opinion which confirmed the original diagnostic analysis.
I had the 2nd shop (Nathan's Auto Repair, Fayetteville, NC) fix the purge solenoid, but advised me that he could not fix the car's computer and referred me to the Crown Dodge dealership here in Fayetteville to have the car's computer reprogrammed.
Well the service rep "Julia" was insistent that their service center run another diagnostic. I explained, that I was referred by my mechanic (Nathan's Auto Repair) who had already repaired the purge solenoid and that the PCM needed to be reprogrammed. I went on to explain, that I had 2 different mechanics run diagnostics, both of which came to the same conclusion, which again was to reprogram the PCM.
But again I was given more reasons as to why Crown Dodge should do another diagnostic; "to make sure there was not something else that might need to be fixed". Julia, said that if it was just the PCM that needed to reprogrammed then I would be charged for the PCM reprogramming, which is only $85. I reluctantly gave the "ok".
Julia called and advised that my purge solenoid needed to fixed, along with some type of pump and the PCM. I called Julia and explained that the purge solenoid had already been fixed and that they don't need to "fix it". Julia insisted that my car was leaking fuel. Now Crown Dodge wants to charge me $477.xx.
I offered to let her speak to my mechanic who diagnosed and fixed the purge solenoid but Julia refused. I advised that I would have to call her back after to talking to my mechanic at Nathan's auto repair.
Nathan's auto repair is on vacation. I am afraid that Crown Dodge may have damaged my vehicle to charge me more money. What can I do about this situation?? Any help is appreciated

Henry
Fayetteville, North Carolina
U.S.A.