notice of approval:2 sent but not received

[skarma]

So my case (i130) was approved back in July 2014. Recently I realized that I had not received the formal NOA:2 letter (I did receive an email stating that my i130 was approved however) so I contacted USCIS. After 3 weeks they sent me an email stating that they had sent me NOA:2 back in July 2014 and don't any record of postal service returning it And asked me to fill out i824 form to get a copy of my NOA:2 that costs $400. This is just absurd. I have received all other documents from USCIS just fine until now. For people with a similar experience what did you guys do to tackle this situation and how long does it take for i824 to get approved. NVC hasn't even received my case yet. Turns out they didn't send my file to NVC after it was approved. They had it stored in USCIS office. Do I need to have NOA:2 with me for NVC to receive my case or this letter is something that I need to have while filing for i485 later when my priority date becomes currents? I don't want this situation block NVC from receiving my case. My priority date is feb 27 2014. Any response is much appreciated.