Cal State Fullerton

So my parents bought me a t-shirt from Cal State Fullerton (where my dad now works) but it was just showing a little too much stomach for my taste. My dad had to go pick up his pay check today so I went along to exchange my shirt. Little did I know how difficult this would be for the cashier to grasp. So we go in and I walk to the register with bag/shirt and receipt in hand. I tell the girl I would like to exchange the shirt for a larger size. She stares at me blankly for a second then says "wait.....soooo....you want to change this one for one just like it....but bigger" I politely respond with a simple "yes I would like a larger size" as the lights turn on upstairs she says "ohhhh ok just go ahead and grab a new one." So off I go and unfortunately the larger size is wider not longer, so I must find a whole new shirt. After a couple minutes I find a replacement thinking "this should be good" as I walk back to the girl. Thank goodness there is a manager type girl standing nearby as I tell her I would like this different shirt instead of the too small one. She just stares at the manager. So the manager explains that she should refund the shirt onto our credit card and then sell us the new one. Well we didn't have the credit card so the manager says she will be right back as she goes to get a gift card so she can refund the money on this and then use it for the new one. The original girl just blankly stares. She returns and hands the girl the exchange and walks away. The girl starts to do the refund and then suddenly the lights come on again and she says "ohhhhhhhh I get it." So when she refunds the shirt she has to also take off my dad's 10% discount so that it will put the correct amount on the gift card. Well then she rings up the new shirt and is very confused as she figures we still owe her a couple of dollars. I then explain that she needs to now discount the new shirt....again the lights come on and I see understanding. The new shirt turns out to be a dollar or so cheaper and thank goodness she tells us we can keep the gift card because there is still money on it....she did figure out that one on her own.