Out of box failure

I have honestly became extremely frustrated with MTN . i have ordered a phone last week friday with the thought of connivence as im busy whole day with clients . My phone arrived Wednesday , it have tried to connect it with my current phone , it was busy updated . The updated was completed before 9 , i left attending to a client for 2 hours , the phone was still on the loading page for the update . I rebooted the phone thinking maybe its frozen . MY WORST MISTAKE , the phone started malfunctioning as i couldnt enter my password nor reboot the phone at all . I took the phone in same day as im not going to sit with a BRAND NEW broken phone . NO ONE communicated i will not be receiving a new phone i need to wait 7-14 days in order to hear back from their repair people . With that being said the phone was taken for a booking & i still have not received a reference number . I phoned last night once again asking for my reference number , i was suddenly told i need to wait 21 days which might be longer due to the public holidays . Anyone can go back & say i have not handed a phone in & then i end up paying for a phone i have never used . Their line is constantly ringing . I am so fed up trying to phone in & waiting for someone to help