Need to delete mobile device access to 365 Mailboxes

I'm trying to write a simple PS script to remove EAS partnerships to a mailbox.  This only needs to be done 1 by 1, but Ideally I could import a CSV for it.  The CSV import I think I can do, but I'm having trouble with the 1 at a time script.  I'm really basic when it comes to PS so I'd appreciate any help - for each and variables are super confusing.  

This is what I have:  

$User = Read-Host -Prompt "Who's Mobile Devices are you going to nuke?  Enter username"
$Devices = Get-MobileDevice -Mailbox $user
ForEach ($Device in $Devices) 
    {
        Remove-MobileDevice $Device
     }
Clear-Variable User,Name,Devices

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But I keep getting this:

Cannot process argument transformation on parameter 'Identity'. Cannot convert the "Persons Name\ExchangeActiveSyncDevices\iPad§Q5F3123456KHLAGK41P7VO" value of type 
"Deserialized.Microsoft.Exchange.Data.Directory.SystemConfiguration.MobileDevice" to type "Microsoft.Exchange.Configuration.Tasks.MobileDeviceIdParameter".
    + CategoryInfo          : InvalidData: (:) [Remove-MobileDevice], ParameterBindin...mationException
    + FullyQualifiedErrorId : ParameterArgumentTransformationError,Remove-MobileDevice
    + PSComputerName        : outlook.office365.com

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Then I'll do

Set-CASMailbox username -ActiveSyncDeviceIDs $null

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as a finisher.  

What do you think of this process?  

Since I know you're curious, we just migrated to G-Suite and I want to prevent people from accidentally accessing their 365 mailbox on mobile.