Mango's Damaged Sport Shoes in Just One Month

A month ago, I bought a pair of athletic shoes at Mango. I've only worn them maybe three times, so how did they get so worn down so quickly? The leather is starting to peel off, and the edges are coming apart. If I keep wearing them, they will get worn out completely. How can a well-known brand like Mango make products that are this bad? I can't figure out what's going on. I want a refund for what I bought. Shoes are made to last for a long time, not to fall apart in a month. Even goods from the market are of higher quality than this. As soon as possible, I want either a free replacement or a full refund.