Understanding your government-protected rights is the key to overall financial security. And you're all for that because you know every penny counts. Get in the habit of checking your banking statements each month: they're often fraught with errors. And when you find one, contact the government. The fair credit billing act (along with other legislation) provides federal protection in the event of erroneous accounting. In writing, provide your account number, a statement of the error and dollar amount, and the reason for the mistake.