Unfair treatment

I bought a 2 piece conti suit in December 2021. Only to find that after 2 weeks it's small for my partner an we put it back in its package. Because I bought many other things at pep store in jewel city that day I misplaced the slip. I went and asked if I can just exchange it for a bigger size but I lost the slip they said no it's impossible, I called the pep call center 3 times that day to ask the same thing an I was given the same answer. I was disappointed and I thought since it's still in its package n it hasn't been worn I can get help, to my surprise I did not. Okay so I tried accepting that I lost R250 on that item.

Now, things changed when yesterday I went to the same pep store in jewel city, and witnessed a lady who called almost everyone in there 'chomi' meaning friend... I was there to buy the rest of my daughters stationary when I witnessed that lady telling the ladies there in the store that she does not have the slip with her it was left somewhere but she needs to exchange her sons blue school short (of which i saw because I was next to her). When I was busy taking the stationary she was assisted in looking for the correct size... This I must mention that it hurt an cut me deep that pep div of pepkor has such ************** in their stores. I work with clients myself as I am in retail... But the unfair treatment of that I was declined to make an exchange because I lost my slip and someone else was able to do so is entirely not the kind of integrity a retail store should have. The store n company is because of its people so if customers are treated unfairly because of the relationship type they have with your employees I must say I will not take this lying down. I wrote this because I was hurt that I didn't even want a refund it was only an exchange of size... I paid using my bank card and I was ready to provide proof of transaction even date an time. Now what is this called?

Pep store clothing in jewel city