When you upload a list of contacts using the CSV Upload we create a separate file in the background.  You can delete that file and all the contacts in it.

Here are the before and after pages to look for:

Note 4,830 contacts in the Contact Manager (before):


Then look up the CSV lists under Basic Settings | Group Email | Option #6 - CSV Lists.  I want to delete the third list down (it has 551 names in it):


Upon deleting the list, I receive a confirmation message:


And now when I return the Contact Manager we see that I have deleted the 551 contacts.


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