Restored iPad 2 3G and now locked out requesting icloud details

I manage an IT team and our sales staff have approx. 10 iPads and 20 iPhones shared among them.

People leave the organisation for various reasons and seldom are happy to provide PIN code or icloud details to reset the devices they had.

In the past I have always performed a reset via recovery mode and this has cleared the PIN request and also iCloud details.

With more recent updated to iOS this has been blocked and the device is useless without an icloud user name and password.

My problems are;

1. Employee left on bad terms and will not provide details

2. Don't know icloud user name

3. Don't know icloud password

This is an iPad while older, still suits our needs which we purchased brand new legitimately.

It appears that I have no options and now have a brick on my hands.

Can anyone offer any suggestions.

Cheers