CHRYSLER FINANCIAL Lease End/Disposition Fee, Internet

After 3 years of leasing my Jeep and paying every single payment ahead of my scheduled due date, I decided not to purchase the vehicle and instead used it as a "trade in" at a Nissan Dealership.  Both the dealership and I independently obtained payoff quotes which were the same.  The Nissan Dealership paid off the Jeep (including the one remaining lease payment).  Two weeks later I called Chrysler Financial to make sure they had received payment and that my account was closed.  I was told everything was paid and it was closed.  Then a week after that I received a statement for $800 which was made up of the last lease payment (which they had already received because the payoff was higher than the residual by exactly the lease payment amount) and a $425 "disposition fee".  

According to everything I have read the disposition fee is for Chrysler's cost to clean, remarket and resell the vehicle.  Chrysler NEVER touched the vehicle, it went directly from me to Nissan.  Essentially, I sold the car for them and this fee is absolutely bogus.  I have talked to numerous customer service representatives at Chrysler and have gotten nowhere.  They can't even figure out that the last lease payment was in fact paid.  I was told recently that they had finally figured it out and that it would be credited in 2-3 days and I'd get a new statement but that they couldn't provide anything in writing stating that they'd remove it.  I'm currently starting the arbitration process because I do not believe I should give them $500 for something they had absolutely no involvement with.  I'm currently receiving 2-3 phone calls per day regarding my "balance due."  I will NEVER buy another car from them in my life.