How long do I wait.....

[madiba]

I got married to an USC and I went for my adjustment of status interview in May this year in Philly and everything went fine. I was told that I would get confirmation a few weeks after wards. I did not get a confirmation and I waited the 60 days per their procedure. I called Customer Service after 60 days and they just said the case is still being processed. I requested a referral and was told that I would get a response within 30 days. I did not get an update within 30 days...I called back...I asked for second referral...again did not get a response and when I requested a third referral I got a letter three weeks after to say that the case is now at the National Benefits Center and additional review is being conducted and that I can call back after 6 months. Is this normal? Do I have any other options to get this done sooner because it seems like its never ending? Can I write a letter of complaint to anyone?