Customer service and exchange policy

I purchased clothes on the 15/09/2015 at Zara Sandton city for my brother. The jacket purchased was too small and I asked him to go exchange it for a proper fitting size. When he got to the store to ask for the exchange to a bigger size, he was told that they is no in house customer service and he needs to send an email to request for the exchange due to the fact that the cash receipt was outstanding. I sent a mail to the their customer service explain that we request an exchange, the item has not been worn, still has the price tag and that it is a current item on sale. Zara emailed back informing me that they will not be able to assist me as i don not have receipt and that I need to read an article link on there policy to be informed about their policy. I find it a great inconvenience that Zara doesn't have an in-house customer service, that I have to do unnecessary administration work to get help. I feel that this is a very impersonal approach by the retailer when dealing with their customers. It also show that the store manager has not decision making power to assist customer because we have to revert to sending emails and approval which prolongs turn around time.