Disapointing service received from the online store

I ordered an item online and the item that I received is incorrect.I have sent various emails to Foschini but for some reason they can't seem to grasp the fact that they sent the incorrect item and they need to rectify instead they are telling me that they don't do swap outs...they made a mistake instead of delivering the item that I ordered they sent me something else.The only answer that they giving me is that they will collect the incorrect order,how does that help me if I am not getting the item that I ordered and paid for?? Where is the customer service here?? they completely disregarded the fact that I paid for an item that I didn't receive and I'm sitting with something that I never wanted.. I requested a manager contact me on numerous emails which was ignored and the complaint was marked as resolved...Highly pathetic service