Well.

1) If you're in the U.S. just open a complaint with your State's Attorney General, because if you've been hit, many others have too.

I'd also open the same complaint in the State of domicile for the company, if it's a U.S. company.

2) Start a PR campaign, appearing on Radio, TV, Podcasts, speaking for Meetup groups, taking about the bank + any parent company + also any countries involved.

This includes for major shareholders in the bank or parent companies.

Create enough press where revenues drop off + you'll get your money back.

3) Lease a server from OVH (no U.S. connection) + setup a Website about this problem.

Then place an offer of sale on your site for $1,000,000 USD, so the bank + parent company's have a clear indication of how... displeased... you are with their business practices...

4) If you've never done this before, hire someone who has to walk you through the process.