How do I file a claim under TurboTax's maximum refund guarantee? TurboTax incorrectly calculated my balance owing. How do I claim my advertised refund?

The maximum refund guarantee is described here: https://ttlc.intuit.com/community/charges-and-fees/help/what-is-your-maximum-refund-or-tax-savings-g...

I meet all of the conditions to claim the refund. However, there is no obvious way to submit a claim. All roads lead to the community forum.