Product: Consumer Loan

My father died in XXXX XXXX. At the time he leased a vehicle from GM Financial. I returned my father 's car to the dealer in XXXX XXXX and GM Financial sold the vehicle at auction on XXXX/XXXX/XXXX resulting in a surplus. It has been nearly XXXX months and I can not get GM financial to send me the refund. This is the last outstanding item before I can close his estate. I 'm asking your help to get GM Financial to send me the refund and close the lease account. 
I attached XXXX documents. The first is a statement GM Financial sent after they sold the returned vehicle at auction. The second document is a copy of the monthly bill they keep sending me seeking {$970.00} in property taxes. That amount applies to all of XXXX and has not been prorated based on the date of sale ( XXXX/XXXX/XXXX ). It also does not apply any of the surplus from the sale. 
The paperwork I received after the vehicle was sold indicated that there was a surplus of {$1700.00}. But it does not appear to be applied correctly to the account. Total costs related to the sale ( line XXXX ) are shown as {$710.00}, but Credit : Surplus Received ( line XXXX ) also shows {$710.00}, not the actual figure of {$1700.00}. Also, the subsequent bill for {$970.00} in property taxes has not been prorated for the partial year nor does it apply any credit from the surplus. I finally spoke with a customer service representative on XXXX/XXXX/XXXX who agreed that after making these corrections I should be getting a refund of {$570.00}. I 'm still waiting. 
I 'll also add some other information about my whole experience in this process because if I do n't tell anyone they ca n't make any changes regarding how they operate. When I first called to report that my father had died and I asked what to do with his car, I was told someone would call me back. I did receive a few voice messages from someone saying they were calling to " follow up with me, '' leaving only a first name and a toll free number. The callers did not identify themselves as being from GM Financial or state what they were calling about. If a family member has just died and I receive a suspicious call like this, why on Earth would I call the number? Thinking maybe it could be GM Financial, I looked up the number online and found no connection to GM Financial, but I did find postings from other people with a similar experience, wondering who could be calling them. In retrospect it probably was them, but I was never sure. I eventually managed to work with the dealer and return the car to them to hold for GM Financial. The car was sold at auction and I received a package indicating there was a surplus due from the sale. For months I 've been trying to collect. When I called the main customer service line, I was told I needed to speak to the lease recovery department. The problem is the lease recovery department is a voicemail box, not a person. I 've never had any of my messages returned. Only when I filed a complaint through their website was I able to get someone to call me back ( on XXXX/XXXX/XXXX ). In the meantime, I continue to receive a bill every month for the ( incorrect ) property tax. No one seems to be taking action on this. I understand that when a lease holder dies it is a default- but there really ought to be a process for families who in good faith are just trying to return the vehicle to the leasing company and resolve the account without this nearly nine-month ordeal. And after all they got all the money they were owed- I have not.