The bank has to follow IRS regulations and the law, or be penalized (up to and including having their right to host HSA accounts be taken away). You need to show to that bank that they made a mistake, so that they can recharacterize the deposit without violating IRS regulations. Maybe you could also try and show that their rules and procedures were unclear so that a reasonable person could not follow them. Otherwise, you need to sue the bank. It has nothing to do with me.
