Paying for a phone MTN doesn't want to release to me

With reference to ***

I upgraded around 22 December 2020 and by the second week of January 2021 my phone had a hardware issue. The end result was that MTN will replace it with a new unit. The dealer in Lichtenburg NW already sourced a new unit for me, but cannot release it as the Repair Centre delays providing a reference so the unit can be released to me.

It is now 3 months and I am still without a phone. The Repair Centre seems to not be able to provide any reason for the delay. I would really appreciate if management can intervene so the unit can be released to me without any further obscure delays.