Sorry that happened to you.

As some HNers know I have a long-time hobby of working customer service state machines, and I'm going to take the liberty of writing the most effective resolution path here for the general case, in case you or other HNers ever need to solve this.

Live chat is probably staffed by external agents and they may have the least ability in the various tiers of the CS hierarchy to help with problems, particularly hard problems requiring substantial judgement. Your princess in in another castle. It is quite possible that there is a business decision made to not let live agents speak to you for fear that a scammer will outmaneuver this tier of agent into getting a reinstatement by pretending to be a legitimate customer confused as to why they suddenly had their account deactivated.

There is a team which makes these sort of decisions (even if they also support teams which implement computer systems that make these decisions at scale), and they also unmake these decisions. You generally can route messages to that team by going in through email support, particularly email support for businesses.

If you cannot, there is also a team which handles internal escalations, and your objective is to find a public-facing individual who will file a ticket with them. This always, always, always includes the Legal department and Investor Relations, and may include e.g. their Comms people, social media people, etc etc. For businesses which tend towards the traditional/stody, I generally used to recommend paper letters to Legal/IR/Office of the President/etc, but for businesses which trend towards tech industry (and increasingly in finance), at messaging them on Twitter from an account that looks like very plausibly a human will often achieve the same effect.

Ignore basically everything they say in your message to the person attempting to achieve an internal escalation, and stick with the facts of your business relationship: I've been a user for N years, believe my account was deactivated in error, wish to continue being a user, and would like to reverse this decision. What information do they need to quickly come to this decision? In the alternative, can they please justify it in writing with specificity to you; you've already read the material they sent you but it clearly doesn't apply to your case.

It is generally not instrumentally effective to be angry.

The symptom you are detecting is downstream of a larger set of business decisions which weren't made for malice. Those decisions have a false positive rate. The business made a series of decisions with regards to false positives, customer support costs, escalation pathways, cost to operate them, etc. All of that is irrelevant to you, though; you just want to present like a professional who wants their account back, and in particular, you want to present like a professional who is very organized and motivated. Organized and motivated professionals who are savvy enough to write Investor Relations to get what they want are the start of a lot of stories which have cost e.g. financial firms a lot of money, because they're capable of collecting paper trails and submitting them to e.g. regulators, and they're detected and dealt with early in the process.

Best of luck and skill.

Disclaimer: comment written in personal capacity. I have some amount of knowledge of how this works professionally and some amount of knowledge from spending years ghostwriting letters into the financial industry on behalf of people who, demographically speaking, generally do not resemble the typical HNer with this problem, but who also felt incapable of avoiding the runaround.