Mango Denied Size Exchange Because of Lack of Receipt

Around May 8th, I went shopping at the Mango store in Ankara Ankamall and got something new for my wardrobe. But when I tried to swap it for another size, I ran into a problem. They wouldn't help me because I didn't have a receipt. puzzling really... what kind of era is this where you can't even do a transaction without a receipt? this is the first time I've been so frustrated! Now I'm stuck with this thing that doesn't even fit. Also, looks like I'm in a bit of a pickle. I'm stuck with this thing that doesn't fit and I can't even swap it for the right size. what can I say, Mango, a big brand and all, can't even give us a decent shopping experience.  I've never dealt with this much trouble before. It's a bummer that just swapping sizes has to be such a pain when it's so simple to find the required info right there in their system.