Poor service being rendered

Good day I have a cellphone contract with MTN that I also took out an insurance on I recently lost my Device and made a claim I was told that the Divice has been dispatched and it is now with courier IT at polokwane about a week ago when I called on Monday the 17th I was told I would receive my phone by 21 of December today when I called in Deon from Courier IT told me they don't have the device as yet when I called at Mtn also and they insist the device was dispatched and I should've received it by now I'm so disappointed and hurt I had hoped I would have a phone by now please assist