MTN head office is the worst!

My wife is an existing customer of MTN for close to 20 years. Went into an mtn store on the 5th June 2022 to upgrade her contract/phone. Was told the plan she is on needs to go up by R100.00 but it would need to be approved and this would not take long. It's been a week and no feedback from MTN. Went back to the store and they cannot tell us why mtn isn't approving R100 extra when all paper work is in order. Store says it's a "glitch" on MTN's new system. How does mtn not have a temporary fix for this "glitch" after so much time has passed! Some form of communication from MTN head office would be appreciated!!! They have lost the plot with their Customer service!!!