Waiting for Green Card for 180+ days now, pls help with filling out some basic info.

I've been waiting for my permanent resident card for over 6 months now. My 2 sons with whom payment was made at the same time, and all 3 of us even share the same DOS Case ID reflecting that. They received their green card in 2-3 months, but despite all information being technically the same including the address, nothing has come so far.

I went to 3 infopass appointments and now that it's been so long, they told me to just file an e-request.
I'm trying to file an e-request via the USCIS website right now. I'm almost done filling everything out, but just 2 questions if you don't mind:


1. Form #: My understanding is that the green card is I-551, but that option doesn't exist.

2. Date Filed: I have a receipt that I paid for the green card application with me and my 2 sons' A-#'s on that payment receipt made on Sept 8, 2018. Is this the "date filed?'
Thank you.