horrible attitude towards a loyal customer

My mother in law bought my son a shirt and pants from zara and I never got a chance to return it as it does not fit him. I was out of town and only got to the waterfront after having it for just over a month. Items are both brand new with all tags attached and the manager completely refused to exchange it. I don't want the money back just to exchange it for something that with fit my son. Cwenga told me he was the highest person of authority that I could speak to which he was not. He wouldn't even hear my reason because I had no idea it had to be exchanged within 1 month exactly. my sister told me a week ago a \white"lady made a scene and they gladly exchanged her items which was also returned more than a month. I was absolutely put off and completely disappointed in zara being a very loyal customer """