Appalling Service from MTN

I am completely appalled at the level of service from MTN. Being sent from pillar to post regarding my new phone still under warranty whose screen just blanked out, with small dots. Not offered a courtesy phone, instead was advised I could cancel my contract if I so wished - offered a number to call but strangely not offered to make a call in store. Contact details of store: MTN Krugersorp, 21 President Square, Krugersdorp, assistant: Phumza. I need a new phone. 3 complaints logged on their Twitter handle sent - 3 different days, DM sent with details as requested - no response, no follow up or acknoledgement of my complaint. It's been 3 weeks. Another complain logged on their website including another email to their customer care. No avail. #MTNServiceFail