Telkom DWR-730 mobile router - unable to connect

Purchased the D-Link 3G MiFi Router yesterday, 5 October 2015 on the R649 special. Followed the very brief instructions but unable to connect to the internet on my cellphone or on my computer. Went back to the store at around 4 pm today and left the Telkom offices at 6.10pm with a product that still does not work. I have spent around 3 hours of precious time (today and yesterday) trying to get this issue resolved and I just cannot do this anymore. I requested a refund but this was refused. Accolades to the staff who assisted though - polite and professional and did all they could to get the sim card connected but all to no avail - the device does not even work in the assistant's cellphone. So, it has been referred to the Technical department for resolution. The bottom line is that I have a brand new device that I cannot use (need it now, not tomorrow or the next day) and I simply want to return it, save myself the problems and get a refund but this has been denied.