Calvin Klein T-Shirt's Poor Fit Disappoints Customer Despite $59 Price Tag

Last Friday, I bought a Calvin Klein brand t-shirt from the Calvin Klein website as a birthday gift for my wife. I chose an XL size based on the size of a t-shirt she already had at home, but when the product arrived today, we saw that the fit — especially in the back — was excessively loose and didn't match the expected cut. Since we bought this product trusting the fit of another Calvin Klein t-shirt my wife currently wears, this difference in cut was a serious disappointment for us.
I washed the t-shirt at 30 degrees, thinking it might shrink and improve the fit a bit, but even after washing, the looseness and sizing problem remains exactly the same. I paid $59 for this product, and I can't accept that a t-shirt at this price would have such a problematic fit. Since I threw away the receipt and removed the tag, I assumed I wouldn't be able to get a return or exchange, so I haven't contacted customer service yet.
Even though I don't have the receipt or tag, I'm asking that you help by looking up the purchase record in your own systems, and offer at least an exchange or another solution for the fit problem we've experienced with this size. I expect this issue caused by the product's fit to be taken into consideration and to receive a positive response from you.