Early Upgrade

I've been with MTN for many years now, I am very frustrated that they Service Champion promised me on 11th March 2020 to Early upgrade (40 GB for 199 Rands) it will be done within 2 to 4 hours. But I am keep on calling and sending mails, I am not getting any proper response until today. I'm not sure why this is happening but this is false marketing and very inconveniencing.