Meta refuses to delete my old account

I have verified myself live numerous times with a chat agent via facebook regarding an old Instagram account of mine, and they refuse to delete it. I don't have access to the old account. It is a dead account that locked me out a long time ago when Facebook integrated with Instagram. I used to be able to log into that Instagram with facebook but ever since then, nope. I have over the last few years needed it deleted for branding but Meta does nothing, 90% of everything goes through AI, and service agents have no power.

I would really like someone at Meta to get in contact with me so I can pull the plug on this old account. Any other platform I have had a problem it has been no problem to do this once I verified my identity. Meta's securiy protocol makes no sense and in iinstances like this seem to have put themselves and users at a dead end which is bad policy.