NO RESPONSE - NEED URGENT TECHNICAL ASSISTANCE

I have spent 5 DAYS (losing business all the while) trying to get my BRAND new Nokia Lumia 630 set up. Email and data work ONLY in WIFI, but the mobile data is not reflecting ON the phone - I have over a GIG of data. We have tested the handset with my husband's cell C sim as well as one of YOUR technician's (Rudi, from Cape Gate, who is helpful and friendly) sim's and data worked immediately in both instances. I have logged on to my profile on the MTN website, which verifies I HAVE data loaded. Drove to Cape Gate stores 3 times this week, done a sim swap, Googled & tried all settings but the phone is not able to USE the data loaded. Last week I lost over R20K of business as I have no data while on the road. NONE of the call ctre no's are obtainable (for weeks now, routing back to the same 2 menus, & cutting me off when wanting to speak to somebody), I emailed customer care (3 different addresses) &spoken to the area manager, Eugene, who promised to get back to me on Friday, and have still nothing. So BRAND new phone, BRAND new sim, phone tested, data loaded, but no data without WIFI=like the data is there, but not \pushed"through/active on the handset. loss of business BAD"""