Poor MTN online contract services

I upgraded my phone contract in the first week of August 2020 through MTN online. I received my handset on the 13 Aug 2020. I opened the box after somedays I realized that I received a wrong phone. I contacted the inbound agent Johan van Nieuwenhuizen to inform him about the error made by MTN. He said I should return the handset to any local MTN owner store and the store will give me IRMS code. I went to MTN Morningside to drop off the handset on the 20th August 2020. I have been following up with MTN since August to date. The response I get is as follows: MTN network is down; this is not a correct number to call and there is never a correct number or person to talk to and MTN store cannot assist with handset contracted online. It has been 3 months and no feedback from MTN. I am fed up with MTN online contract services and I want out.