Our Instagram account got hacked and no one at Meta will help, what to do?

Our instagram account at the SAT - Société des Arts Technologiques, https://sat.qc.ca/en - got hacked 4 weeks ago. We spent two days every week to try to get it back, and spoke to countless Meta persons, bots, etc. to no avail, it's like talking to a wall ; we had 30k-ish followers, which is critical for a tech / art-oriented venue.

https://www.instagram.com/sat_montreal

Posting here in case any Meta employee could have a way to unlock this as we are out of options on our side.