Waiting more than two weeks or a letter????/

<p>I have phoned MTN and i was inside the MTN shop in klerksdorp to ask for my final invoice / cancellation letter on an MTN letterhead. That same day i was told that i will receive it the same day before 12:30, well its now more than two weeks and i still DO NOT HAVE the letter?? I do not know who to beg or ask for help to get the letter??????</p>