Can I exchange my XL ADC t shirt?

I wear a size XS-S. Any way I can exchange my giant t shirt that came with my student ADC membership? Has anyone done this, and how did you do it?

 

I want to give this shirt more exposure than that! Sadly, my nightwear has a very limited audience.

I am female, for the record, but are you saying gents can't wear nightgowns?

I really do hate how XL seems to be the standard. Plus, it's fairly obvious from my first name that I'm a girl. Not that there aren't XL girls, but surely girls my age are more likely to be medium or even large?

I am going to feel sort of silly calling and asking. I will do that, just curious if anyone else has tried/what resulted.