INFINITI of Lynbrook

I returned my lease to this dealership, signed the necessary document and thought my interaction was finished. A month later i got a call from Infiniti financial that my account was delinquent and that i was on the hook for the full car because it was not returned and that they filed a delinquency with my credit. This particularly sucked because I was in the process of getting a mortgage. I contacted this miserable dealership and they said they would look for the car on the lot and get back to me in a few days. After no one getting back to me, I went down to the dealership and demanded written proof that they know where my car is. Their response was "the person who does the leases is away at a conference so they couldn't get it for me". I insisted they give me the document anyways, and they said they will see what they can do. They went upstairs for 3 hours, came down and handed me the grounding documents for my car and although it showed it was returned a month ago, it showed the closed date as that day. Thanks for ruining my credit because your guy forgot to ground the lease. I reached out to them for an explanation and posted on their Facebook account but no answer. So next best thing is to warn everyone, STAY FAR AWAY!