Underlivered handset

I have been waiting for my replacement handset for long time now when i call the mtn claims call centre i am told that the handset will be delivered tomorrow but tomorrow i will be told that i must wait until tomorrow and this has been going on from last week . Thr corier never contacted me or made an effort to call but they say they have failed to contact me. This is causing a lot of incoviniences on my side and my work has been affected . With corvid lockdown a smart phone has become very important in my line of work.