MOST HORRIBLE EXPERIENCE AT ZARA STORE

I purchases a pair of red sneakers @ZARA Cresta mall 2 days ago (Sunday 24/11/2019), I call MOA as it is the only store near me (Centurion) because I want to exchange the pair for a smaller size (no refund requested) they told me they can’t assist me because I cannot find my receipt. 1st of all I was NOT informed of ANY return policy of the product, which I believe should have been communicated with me when I purchased the product, that time I used my cheque card to purchase which I don’t see why they can’t check because the transaction is easily traceable, Camera footage in store should be there as well. On Tuesday (26/11/2019) After work i drove to the store (MOA), the manager there told me that there is no customer care line to call, instead she gave me an email address to send my query to and wait for their response. I sent the email while in store, that time I have 3 days left till the wedding I am attending which I need the shoe for. I went to Zara because I trusted that i would find what i was looking for (as a loyal customer) which I did not expecting this revolting experience. Little did I know.