Can any one solve my doubt on valuation rules 2a(ii)

Can anyone solve my doubt on valuation rules?

Can i claim cenvat credit on excise duty paid against service tax payable ? To be more clear,i am a service provider.I purchased  input goods for providing output service on which i paid excise duty.can i adjust this against service tax payable?

OR

it can be adjusted only if i am a manufacturer and service provider.