Bussiness distribution not working

Hi everyone,

We have developed an application for a large company and are distributing it using a business account. We have codes that we give to users.

The problem is that we released an update for the same app, but users aren't receiving the update automatically as it should be. It's not working. So, we are giving new codes to users as if they are installing a fresh version.

We have contacted Apple, but we haven't received any answers (the suppport its a nightmare mostly people just saying they dont have acess to our ticket case)

Has anyone else experienced this problem? And does anyone have a solution for this?

Thanks.