no slip no service?

Ive purchased a pair of Adidas from footgear Somerset West not longer than 6months ago. Im so beyond myself with the excuse i was given that no stock can be exchanged without a slip. Ive given them a box for what i taught was more proof that it wasnt ****** bt clearly that didnt help me in any way! So what do i do in a case like this as my child cannot wear broken shoes and i paid R399.00 for Adidas which is supposed to be a well established brand. I was trying to sort this out with the manager but all i was told is that his bosses are to strict now and he unfortunately cannot assist me! I can promise that im NEVER buying anything from any footgear again and neither is anyone i know!! FOOTGEAR SUCK AND DOESNT EXIST TO ME ANYMORE