Cotton On Im still waiting for my refund nothing is happening

I bought a pants for my son on Cotton On online. I never received the parcel and l noticed Cotton On They investigated and promised to refund me. Its over 2 weeks now and still no money in my account. I have been e-mailing them as a follow up but no rrsponse. I was promised the refund will take 1-5 working days. Its over 10 working days now still no refund. Im very disappointed on ther service.