users logged on to iCloud using personal apple ID on Organisation iPads

You can't logout from Apple Account from Jamf, Apple removed that functionality. You should have the Apple Account password else you need to reach Apple Enterprise with purchase copy of the device to unlock from the Activation lock.

If the device is added in ABM, you can remove the activation lock without contacting the Apple.

For removal of activation lock using ASM/ABM, the device serial must have been added before the device was activated. As this is a fairly new feature, it might not be available for all your devices.

Otherwise, @shrisivakumarans advice is spot on, contact Apple support to see if they can help. Have all affected device's serial numbers and proof of purchase ready before calling in.

Some companies I have been in contact with have added a clause in their contracts to make sure users log out and confirm Find My has been deactivated before leaving, otherwise the cost of a new device is billed to them. Even some schools have implemented this.

Wipe the iPads, use the activation lock bypass you should have configured Jamf to escrow if necessary. 

Ideally you should have Jamf configured to disallow users from enabling activation lock. In the event you don’t have that configured for some reason Jamf will have the Activation lock bypass if configured to have it, and you can also bypass activation lock in Apple Business Manger. If all of that fails you need to call Apple.

As far as wiping the device, using Jamf to do it with erase all contents and settings is easiest, but you can use DFU mode or whatever method you prefer.

Thanks, Seems like I have to visit Apple store with purchased orders.

Thanks all, We might have to take to Apple Store.