Poor service

Last week I went into mtn to inquire about early upgrade. I was told the week before it would be no problem. I was then told ( on another visit in store) that I had to qualify first. When my consultant phoned the call centre we were on hold for 70 minutes while I sat twiddling my thumbs in store. At 5:05 pm she told me we may as well hang up as the call centre closed at 5 pm. What a waste of time and money. I am seriously thinking of changing service providers. I was also told that if I qualify for early upgrade it is only valid for 7 days- but my phone I want is on order and my take weeks???? This makes no sense..... All I want is to upgrade early, pay the difference required- I've been told 2 different amounts..... And get an iphone 6 gold. Please help, mtn