one month and still no handset

i upgraded a month ago (17 March 2016). i was told my handset will be delivered to me in 7 working days. no feedback was ever provided after that. i called them again beginning of April to understand what the delay was about, i was told the handset was returned to MTN because the Courier couldn't get hold of me. i asked that the phone be sent back and verified my contact details. i was told that would be done, but still i have been calling and all that has been happening is i was transferred to different call centers. this is really upsetting especially because no feedback is provided.