My Mistaken Online Purchase from Mango—I Got the Wrong Brand!

I purchased waxed trousers from Mango's online store. Instead, I received a product from US Polo, not Mango-made. How can Mango send a different brand's product? This has occurred before, and when I spoke to the customer representative, I didn't get a clear answer. When I went to the store for a return, I waited in line for an hour. Treating a customer this way doesn't align with Mango's quality. When attempting to buy the same product in-store, they mentioned it was busy due to a sale, advising me to call. However, they showed no interest, and the item was out of stock before I could purchase it. I seek a resolution for my grievance. This doesn't befit your company's reputation.