Duplicate threads merged. Do not post on a topic more than once.
You were already given best advice above. Stop calling USCIS and the embassy, it’s a waste of time. Get on a plane to the US. There are no visas or anything else needed. You’re not helping yourself by continuing delaying buying a ticket. BY LAW lawful permanent residents cannot be refused entry. Cbp might pressure you to sign I-407 but they CANNOT force you to, as I said by law they have to admit you. They can refer you to the immigration court but that’s highly unlikely given that you’re only gone for a year. There are some people who were out for years and successfully returned. Please do yourself a favor and book that ticket to the US right now.