Not receiving phone calls

I migrated to a new contract on 25.06.2021

Since then, I cannot receive calls. I can make calls, but I cannot receive calls. My phone keeps on going to voice mail - every morning FNB follow up (ref ***) that they are working on this - but I am not seeing any results.

In the meantime, i am getting pressure from my work as no one can reach me. This matter is very urgent!!!