Kingsmead shoes

Kingsmead have an exchange policy on their receipts that u can return shoes if there is a defective on them within 6 month. Bought shoes on 28 July 2023.both soles of shoes cracked. I took them back and was told it's because I wear them to much ...I didn't ask for a refund just wanted an exchange and yes I do understand they have a CPA guideline but how can u say I'm wearing my shoes to much. They are only 2 and 1/2 month old surely soles shouldn't cracked within 2 and a 1/2 month.