Poor service on exchange... Disgusting

I am highly dissatisfied with truworths services and how they treat there customers. I purchased a pair of shorts and wanted to exchange them for a bigger size. I unfortunately lost the receipt somehow but didn't think it would a problem as I just wanted a bigger size. The pants still has a tag on hasn't been worn still in a sellable condition and within the 30 day return policy. They absolutely refused to assist me due to me not having a receipt. This is a disgrace, i don't want my money back I simply want a bigger size. The manger had no care to assist me, there customer service line is even worse spoke to zandile who laughed at me when I expressed my dissatisfaction. I will be closing my truworths account immediately. I now have a pair of pants that are brand new that I can do absolutely nothing with simply due to the unwillingness to assist me. They didn't even try and find a way to help me. I have proof of the purchase on my bank statement. They just don't care.