AZUMA Leasing

When I used Azuma Leasing I had nothing but trouble with the billing department. I moved out years ago, ending my lease with them; paid in full, goodbye and good riddance.
Now it’s literally EIGHT YEARS later. In the past four months, I’ve been getting collection emails, claiming a past due balance and a «cleaning fee» from 2004. At first I dismissed these as scam emails, but no, they’re real. Azuma has kept my information in their computers for almost a decade, and now either due to poor organization or possibly falsified claims, they are threatening collection activity against me (action they cannot legally pursue.)
Letters to their billing department go unanswered. I’m so furious.
Beware. Beware!
Update: I never got a response or result using traditional customer service channels until I posted a message on their Facebook page (which they promptly deleted after the weekend.) However as a result I received an email admitting the error was on their end (new billing software) but they still tried to say my last bill had never been generated until now. Either way they deleted the charges a week later.
I won’t give them extra stars though; Facebook should not be their outlet for grudging conflict resolution. Letters sent to their billing department via USPS should be given far more attention than rants on Facebook.