changing Log-On Account for service with powershell - powershell

Question

I have csv file with mass data - service name, computer name, account name.
I wrote a script that:
takes the data from the file
renames for each service the name of the user who runs it
generates a password for it
updates it in AD and in the service itself
then update an external file with a saved password
The problem is that I get a null error for the command Get-WmiObject in the stage Load List Servers to $ServiceObject
I'd love help if possible.
I think there should nested foreach but can't find where
$Computers_list = Import-Csv -Path "C:\PS-Script\Service(sid)_prod.csv" # (CSV file with 3 columns, StartNameCredential, ServiceName, ServerName)
$NameCredential = $Computers_list.StartNameCredential
$ServiceName = $Computers_list.ServiceName
$ServerName = $Computers_list.ServerName
$i = 0
foreach ($ServerName in $ServerName) {
# Generate Random Password
Add-Type -AssemblyName System.Web
$pass = [System.Web.Security.Membership]::GeneratePassword(16, 5)
$ServicePass = $pass
# Load List Servers to $ServiceObject
$ServiceObject = get-wmiobject -Class Win32_Service -ComputerName $ServerName -filter "Name='$ServiceName'"
# Stop Service $ServiceName
$ServiceObject.stopservice() | out-null
# Change $ServiceName Start-Mode
$ServiceObject.ChangeStartMode("Automatic") #Manual \ Automatic
# Update Password In AD for $StartNameCredential
Set-ADAccountPassword -server "sap.technion.ac.il" -Identity $NameCredential -NewPassword (ConvertTo-SecureString -AsPlainText $pass -Force)
# Change Log-On Account for service
$ServiceObject.Change($null, $null, $null, $null, $null, $false, $NameCredential, $ServicePass) | out-null
# Start $ServiceName Service
$ServiceObject.startservice()
# Insert $pass into file
echo $NameCredential[$i] $pass >> SAP_prod_pass.txt
$i++
}
Thanks