As a retail manager myself, i doubt there is nothing that can be done.
Im guessing most shirts are bought through some sort of wholesale/franchise from RFC.
In my experiance, many stores or retailers will never exchange on this, however i hope there is some decent managers who will honour the brand and help you out.
Unfortunaley im in jewellery retail, but always understand the emotional issues involved.
Hint: be nice...its much better than the harsh approach, it only makes us stuck in our ways.
Really hope you get somewhere as its really unfair.
L