For the refundable government fees & taxes, your claim is with the agency receiving them, not with the carrier. However, none of those agencies, e.g. DHS for both TSA and CBP, have a means set up for these claims. PFCs are paid to the local airports authority which could be the state, county, a municipality or a special district.

The only people affected by this are those who cannot use a credit. On the flip side, business travelers have deducted the cost of the ticket and would have to back the deduction out if they received a refund.