Complain-not recieving my refund

Re: Terrible service. On Thursday the 12th of August I returned an incorrectly supp**** part which I bought online and I was promised to be refund within 2 working days because they don’t have what they advertised, however on Monday the 16th of August my matter wasn’t looked at and I was referred Dylan Olivier who said via email my query is with their accounts department, now he is not replying to my emails and I’m not getting response to tell me if at all I will receive my money back.