No help from Mobileplus and MTN including ChannelQueries, terrible service. I am stuck now

I did an upgrade with Mobileplus agent on the 9th of May 2018, on the 15th May, I called Mobileplus to find out the whereabouts of my new phone they told me that DSV(courier company) returned the phone to MTN (back to sender). reason the client said its a wrong order or item?? No one delivered the phone to me. Then they told me that my upgrade will be cancelled because I returned the order, who returned the order?? DSV. did they deliver to me NO. Then MTN sent me an invoice for my upgrade whereas I didn't receive the new phone, Mobileplus has the guts to send my details to MTN to invoice me even though they haven't verify with me if I receive the phone. How come MTN send me an invoice without client confirmation of goods received. I have made attempts by calling MTN and Mobileplus trying to resolove my upgrade cancellation or return the phone to me because I received data, minutes and free data already. but MTN accounts division, channel queries and mobileplus are playing hide and seek, blaming one another, So I am GATVOL becuase I don't have a phone.........its been 11 working days without a phone......and I can't do another upgrade.