Sounds like an office politics problem at IB that someone high up at IB needs to resolve or approve the resources to resolve.
There's no reason an app can only be updated once every three or six months.
The average App Store review process is currently running about six days.
I get that your department doesn't really have control over the app experience as it's a different group that manages that product, but someone who does have control needs to understand the current process is leaving a lot to be desired.