Careless, worst and pathetic service

I cancelled the upgrade from the 28 August 2015 with Sumaya at ***. She advised me that she can cancel item as soon she receives verification that phone has not been delivered which will take 8 days. I never received the phone and I have phoned her several times to cancel. I also received notification from courier delivery cancelled. I have visited the branches, phoned the MTN call centre and everybody has tried to cancel this upgrade but its only MTN Velocity that can cancel this upgrade. I'm at my wits end as Sumuya has promised me to cancel but never did. I am so frustrated as I need this upgrade to be cancelled for another handset upgrade which has limited stock. I hope I'm not charge for a stupid upgrade which I have never signed or received handset. PLEASE PLEASE PLEASE CANCEL UPGRADE I NEVER RECEIVED THE HANDSET(I DONT WANT THIS HANDSET) AND HAS PHONED SEVERAL TIMES.