Complaint Regarding Refusal to Exchange

I am writing to express my disappointment with the service I received at Side Step, Zevenwacht Mall. I purchased a pair of Adilette Slides on 11 December at 17:36. When I got home, I realised that the size 9 was slightly small and decided to return to the store the following day to exchange them for size 10. Due to heavy rain in Cape Town yesterday, I did not wear the slides at all. However, the store refused to exchange them, citing dust under the shoe as the reason, even though the staff could clearly see that the slides were not worn. The dust was already present from being handled and fitted by customers in-store, as shoes are generally given to customers to try on when checking sizes. I still have the slides as proof that they were never worn outside. I find this policy and the way it was app**** to be unreasonable and disappointing. Based on this experience, I would advise customers to rather shop at more reputable stores such as Sportscene or TotalSports, where exchanges are handled more fairly.