Hi Justin,
Thank you for taking the time to give us your feedback. We're sorry to hear that the Shelly Shirt didn't work on this occasion, and we'll be sure to pass along your comments to our production team regarding the sizing.
We do offer exchanges, so if you need any assistance in generating in a return please contact customercare@waxlondon.com and we'd be happy to help.
Best wishes,
Wax London