Shocking service!!!!!

Seriously!!!! MTN is useless!!!! I took my iPhone 7 plus to the river horse valley repair center on the 30th of July and that same day I got a reference number for my phone to be replaced, I then took this number to MTN In gateway where I purchased the phone and I was told that there is no stock, so I asked the question as to when they will receive stock and I was told that they will call me, about 3 days later I went back to the store as they NEVER answer the phones!!! And I was told once again there is no stock.... 2 weeks later I am still told there is no stock I have called MTN direct and the are just as bad, completely useless... MTN retail shops are completely unprofessional... I then went out on a mission to see if i could find one in any of the MTN shops and I found one at la Lucia mall but they can't give it to me because they are a MTN Direct Store and I purchased mine from a MTN Retail shop so they can't give me the phone again I don't see how this is my problem....

Please assist immediately!!!!