On-line add change - experience & questions

Filed 485/765/131 at the end of July and moved to a different state at the beginning of Sept. Did on-line AR-11 yesterday and got confirmation #. However, when I proceeded to change address on the pending cases, I could not do anything with 485. Was sucessful with 765 and 131. Then I got an e-mail today saying they can not update 131 since I did not provide receipt # or A#. But the same e-mail also said they've updated my address on pending cases. I called them up and was told that means the updated on my 765 is done and I need to do update for 131 with A#. My question is the A# requested on AR-11 is from the Alien Card. I have not received anything for my filing yet, let alone Alien Card. I do have one A# from my 140 approval. Shall I use that one? Also, I was told that I can only change address over the phone 90 days after my filing and if I have not received any receipt. Is this true? The person even admitted that anything sent to my old address will be returned. So it's very possible that I won't get anything within 90 days just because I moved. Is this true? Can someone share your experience and advice please? Thx!