Get bitlocker keys remotely

Manage Bitlocker keys for enterprise network, gather the keys and log any computers offline that resulted in not getting bitlocker key for that computer

below script is not working correctly for multiple computers to be checked for online connectivity write log, get bitlocker or else write log stating computername of machine that is offline, I don't know where I went wrong with my function for the log because all thats happening is log file shows date time stamp and nothing else and I'm not getting any other keys

function log($string){
write-host $string
$timestamp =  (get-date -format dd-mm-yyyy) + "|" + (get-date -format HHMMsstt)
$computers = get-content -path '\\computername\c$\users\admin\desktop\scripts\Laptops.txt'
FOREACH($COMPUTER IN $COMPUTERS){
if(Test-Connection -ComputerName $computer -count 1 -quiet){

log "$computer is online getting bitlocker key"
manage-bde -protectors -get c: -computername $computer > "\\computername\c$\users\admin\desktop\bitlocker\$computer.txt"
}
else{
$logfile  = "\\computername\c$\users\admin\desktop\scripts\logs\devicesoffline.txt"
log "$computer is Offline"
$timestamp + " " + $string | out-file -FilePath $logfile -Append -force
      }

}
}