Find the names of customers who have used either the service "Close a policy" or the service "Upgrade a policy".
return customers ;return services used of  #1 ;return #1 where  #2 is  Close a policy  ;return #1 where  #2 is  Upgrade a policy  ;return #3 or  #4 ;return names of  #5
['select', 'project', 'comparative', 'comparative', 'union', 'project']