Refund claim clarification

Sir, a assessee has applied refund claim to the Asst. Commr. of central excise.  When they scrutinised that the invoice value is difference between  ARE1 value and Shipping bill value.  The assessee has claimed the ARE1 value, which is less when compared to the shipping bill invoice value.  Which amount have to sanction whether shipping bill value amount or ARE1 value amount.   Please clarify...   kind of you sir,