BAD SERVICE FROM MTN SOUTH AFRICA

I lost my contract phone over weekend 14/12/2019 I tried to call MTN several times and even went to the shop 16/12/2019 & I did not get any assistance with regards to my Sim swap and blacklisting my ****** phone. The only response that I got from both MTN Champs was the the system gives then an error & it's been 2 days. The consultant at Waterfall Mall Rustenburg (Portia) & others had an attitude & even walked out on me. Apparently the system has not been operating for a month & I fail to understand what is MTN maintenance doing about the system. As a customer it's frustrating & I want my number to be active as soon as possible.

Please assist with my query