MTN LOUSY AT DOING UPGRADES

Sine 01 May, i have been trying to upgrade my two phones. then i was told i am only due 31 May, fine no problem, i wait. Since 31 May, i have been trying to upgrade, i go to the stores and no one has stock, i call online, they cannot help me as i am on the new system apparently, no i tried to do it through the online shop only to be told i am only due 2 july. every time i am due for an upgrade i am being told no its still another month. and NO ONE PHONES A PERSON BACK TO HELP. i have phoned MTN direct since the 01 June and i am still waiting on calls from 6 different agents that promised they will call back. non of the stores answer their calls. NOW MTN HOW EXACTLY WOULD YOU LIKE ME TO UPGRADE MY PHONES??? SHOULD I RATHER MOVE TO A NEW SERVICE PROVIDER THAT WILL JUMP AT ANYTHING TO SEE TO THEIR CLIENTS????????????????