Cell Phone Repairs and Upgrade

I have handed in my cell phone on the 8th August for repairs. I'm not able to get assistance for the MTN Store, nor the repair centre its the 8th September...please advise what you think I should do.

I did an upgrade for a new device on the Sunday at another MTN Store near the Woollies in Carnival mall as well for another line for the S8 with the J9 free. The J9 isn't in stock and the upgrade documents were signed, I was advised that i'd be contacted in the week for the collection. I've not had any feedback here too and when you call the line is never answered and eventually disconnects.

if I do an insurance claim for a replacement device, I will be told I cant yet my phone is needed for business purposes and no one seems to care.

I would like answers for this pathetic service where no one actually cares.