Manage multiple devices (500) in company...?

I manage about 500 Apple devices in my company.

We have a problem to manage apple id in the devices...

Each individual user defines his personal user (Apple ID) in his device (IPad/IPhone).

When a user forgets his access code to his iPhone/IPad, to solve the problem, we need to reset the device data and then to made a new IPhone/IPad.

But, we are required to release the device from is apple user's ID... And we have a problem that the user does not remember the password and sometimes his username ):

It says, the device is locked ):

And they started a bad movie to unlock the device...

Please help me, what is the best way to manage multiple devices?

Thanks

Kuper