Which customers have used the service named "Close a policy" or "Upgrade a policy"? Give me the customer names.
return customers ;return services #1 used ;return #1 where #2 is  Close a  policy ;return #1 where #2 is  Upgrade a  policy ;return #3 or  #4 ;return customer names of  #5
['select', 'project', 'comparative', 'comparative', 'union', 'project']