...so, I added a Department header in the CSV and appended valid department names which are the same as the department OUs, then added some code in the foreach loop:
#Set the OU path for new accounts, otherwise they'll go to the default User OU
$Dept = 'OU=' + $user.department
$MoveOU = $Dept + ",OU=Departments,OU=Accounts,DC=usroboto,DC=com"
I also added "-Path $MoveOU" to New-ADUser cmdlet in the foreach block.