Service tax input taken without payment to vendor

Has the person raised invoice on you? Input credit can be taken based on invoice issued.

I have question A is registered under service tax, he is exporter. A pays st on bank charges etc in foreign money realisation. A want to claim refund of st paid. How to fill form for refund and is this refund will be reflected in st 3 also as A has to snd st3 also for 1.4.15 to 30.9.15. Thanks for reply in advance