never received Green Card in the mail - how to apply for emergency travel / temporary GC?

[LorRie 37]

My green card got lost in the mail by my local post office (they admitted it was their fault and provided a letter stating that) since December 2018. Just recently, we applied for a replacement and went to re-do the biometrics. After the biometrics, the lady said it would take 1 YEAR for me to get the replacement card in the mail. I had no idea it would take that long for them to essentially reprint and reproduce a new card! Had I known this I would not have made any travel plans until I had gotten the replacement card. We've waited patiently for almost 3 years to get the green card so my husband and I can finally visit my family and do some traveling outside the US. However, now that I technically have my green card i'm faced with this "lost" green card issue and once again cannot travel out of country.

We are visiting my home country in August and need a document (or stamp?) that will serve as a temporary green card so I can leave and come back. 
We've been given the run around by the USCIS officers we've spoken to on the phone.. and I am just lost as to how and where to apply for this. I have searched online for this but have not found correct information.
Most recently, an officer we spoke with told us to fill the I-90 - WHICH WE HAVE ALREADY DONE! We are already on the biometrics stage. She hung up the phone before I could ask her more questions.

Our flights are already booked for August and we want to get this sorted out way before our travel dates. This is stressful as it would cost a lot of money to change our flights, which we had to scrounge and save for on my husband's one income (I'm unable to work as I didn't/don't have my GC yet). 

Any advice pinpointing us to the right direction will be greatly appreciated. 

 

[AffableAndy 107]

Set up an infopass at your local office (you need to call to do this at some locations), and ask for an I-551 stamp. If you have the receipt for your I-90, you should be good.

Edited June 11, 2019 by AffableAndy

[Loren Y 2,756]

As above poster stated, you need an I-551 stamp. You may have to call and get a tier 2 person at USCIS in order to get an infopass appointment scheduled because a lot of offices are not letting you schedule appointments online anymore.