Service Item without receipt

 Hi All,

  

  My client has a requirement where ,when i put a service  PO it should not go to receipt else it should ready for invoicing I.e from PO to invoice ,however when i am changing the options at PO level i.e match option 2 way and     Matched to PO still it goes for receiving ,even from item attribute level i have followed the correct steps.Further from organisation level i cant change receiving option because this organization is used to receive other material.I do not have the oracle service module so how can i meet this requirement??