Upgrade catastrophe

Dearest MTN!!

I have been a customer of yours for 15 years! I have been trying to upgrade since 2 August 2021 with no avail. I have tried online (which I always do) I have tried with an agent, I have tried on your app, I have tried via whatsapp with an agent and literally no one gets back to me. I am told they will find out and call me back but NOTHING. Now I receive messages saying “ Yello Customer. Please note there is a delay in your MTN order due to a stock shortage on your selected deal. We will keep you posted! MTN.” and that it.

Please HELP!!