I did not receive a good service at pep lebowakgomo and when I called the customer service I still did not receive a good service by their consultant

I did not receive a good service at pep lebowakgomo and when I called the customer service I still did not receive a good service by their consultant. I bought clothes which are now not fitting me. I lost the receipt. I only want to do an exchange but they are telling me that I cannot exchange because I don't have the receipt. That lady I called she even told me it's my loss. Where can I take this matter to because iam now gonna have clothes that I can't wear.