The case involves a challenge to a refund claim for service tax...

The case involves a challenge to a refund claim for service tax u/s unjust enrichment principles. CESTAT held that refund can only be granted based on the assessment made, not outside it. Refund proceedings are akin to execution proceedings and cannot alter assessments. Appellant's voluntary tax payment without challenging assessment made it final. Without challenging assessment, refund claim is not maintainable. Refund proceedings based on a decision where appellant wasn't a party and without challenging assessment are to be rejected. No need to consider Section 11B of Excise Act. Appeal dismissed.