I have no clue what this module is, but the first thing I would ask is why you are loading the
API twice. Then I would want to look at the code that called the user_delete function to see if it is passing a value for asn that is overwriting the value that you get from pnVarCleanFromInput() when you do the extract($args); Then I would want to see the delete_item function to make sure that it wasn't that function that was losing the value.
Right off hand it looks like this function should work.
-Chris