service tax query

 hey guys i hav one query plz do the needful.person providing services related to handling charges wr he has to pay service tax and he also receives services related to goods transport agency via his agent.in these case he has to pay service tax on GTA because of he is principle and he gets ABATEMENT of 75% on GTA different bill raised for GTA and Handling charges.my query is 

IF GOODS TRANSPORTATION BILL IS INCLUDED WITH HANDLING CHARGES WILL HE GET ABATEMENT OF 75% ON GTA WHICH IS COMBINE OF HANDLING CHARGES AND GTA. 

IF GTA SEPRETLY SHOWN IN BILL THAN WHAT?

AND IF MERGED THAN WHAT?

PLZ REPLY