The problem is that Instagram does not have a normal support, where a live person could answer you. All they can provide is encrypted responses and links to numerous FAQ.
However, I’ve heard that it’s possible to contact the Meta through the Facebook ad account (if you run ads at all). There, at least each case is considered by a real support team. However, I’m not sure that it can discuss the issue of account recovery, since this process is established directly through Instagram.