excise duties calculated on freight while doing MIRO

Dear SAP gurus,

While I am doing Invoice verification(MIRO) for a PO, the excise duties are getting calculated on the material cost as well as the planned delivery cost i.e. in the accounting entries it is showing three different line items for BED, ECS & Secs on planned delivery cost. Can anyone suggest how I can rectify this error.

Regards,

Sai.