Applying for ESTA, or any travel document (vacation) as an ex US Permanent Resident Card holder

When I was little I lived in the US with my family. In October 2007 I received a permanent resident card, however in 2008 I moved to Finland with my family.

From what I understood my family should’ve visited the USA within one year in order to not lose the permanent resident card, however we have lived in Finland for about 11 years now. I was planning on visiting the US this June for vacation and I was confused on the state of my permanent resident card which expired in 2017 and my overall permanent resident status. I wasn’t even aware that I had a permanent resident card until last week when I was trying to fill in the ESTA application and I asked my dad just to be sure if I had any “national identity card issued by any other country”.

A CBP ESTA Officer then informed me that I am ineligible to travel on the Visa Waiver Program/ESTA if I am a Lawful Permanent Resident and I should contact my nearest US embassy or consulate to obtain appropriate travel documentation. First I tried contacting the US embassy in Finland via email and they told me I should contact the US consulate. I tried asking questions from the US consulate on the matter and they didn’t really answer any of my questions specifically. They just said to return the card to their offices and to fill in the I-407 form so I won’t have any problems with traveling to the USA. To me that sounds like I would still have some permanent residence status if the consulate wants me to fill in a “Record of Abandonment of Lawful Permanent Resident Status”.

So I was wondering if there are any other options for me to travel to the states other than by getting rid of my permanent resident status, if I do still have that, which I am still unsure of? I might want to move back to the US after my studies in Finland so that’s why I wouldn’t like to abandon it completely. My flight to the US is scheduled in the beginning of June (~4 weeks), and right now I’m scared it’s too late to get a travel document.

So, is there any way to still make it, and is my only option here to abandon my old permanent resident status?