Powershell handling CSV file

See the example below.

Using Get-Content and ConvertFrom-CSV with its -header parameter to define the csv headers since they are not present in your CSV, you can get an object out of the data.

Then, instead of trying to remove stuff to the original array, you instead build an output "array" using an object which you can modify freely, such as the .net list object.

From there, you can do what you want.

$CsvData = @'
customer 60; SomeLocation; 60
customer 120; SomeLocation; 120
customer 140; SomeLocation; 140
customer 200; SomeLocation; 200
customer 300; SomeLocation; 300
'@

# In your case, rather than the direct csv data, you'd use
#$CsvData = Get-Content -Path 'PATH_TO_THE_CSV' -Raw

$Customers = ConvertFrom-Csv $CsvData -Delimiter ';' -Header 'CustomerName','Location','SomeInt'

# Not sure why you'd use it if you set your target to 140
$Random = Get-Random -InputObject $Customers

# We build a new List instead of trying to remove from the original object.
$CustomersOutput = [System.Collections.Generic.List[psobject]]::new()
#Arbitrary filtering - Notice I do convert SomeInt to an int before doing the comparison. 
# Otherwise, the comparison would be done between a string and an int, which would produce weird results. 
$Customers.Where( { [int]$_.SomeInt -le 140 }) | % { $CustomersOutput.Add($_) }

$CustomersOutput

Result from $CustomerOutput