This is actually an enormous problem for the HOA and you could successfully press this, including through a law suit. Do not just withhold money from your next HOA payment, though. That will lead to enormous problems for you even if you’re right about this.

All that said:

• Convenience fees are usually a percentage not a flat fee. So someone probably screwed up the website.

• it’s very possible the convenience fee is paid to the bank or payment processor, not withheld by the HOA. So they might not be stealing from you.

• In theory, the HOA is a non-profit coalition of your neighbors. So you should give some leeway for honest mistakes.

So, what I would do is figure out whether they keep the convenience fee or pay it to a third party. Just ask them—you’re entitled to know as an HOA member.

If it’s paid to a third party, I’d advise them to update the website and eat the 3% if you can afford to., or ask for a discount on next months fees if you can not (don’t just unilaterally deduct it—that can cause YOU lots of problems). If they keep the fee, then I would ask for a discount in next month’s fees regardless.

Also keep in mind that many HOAs, especially for larger communities, have a hired manager (who often sucks) and a board of homeowner directors (who often but not always suck less). If you don’t get anywhere with the manager, go to a board meeting and talk to the directors. That’s what the meetings are for.