Refund of CENVAT credit permitted when only customs drawback is claimed, allowing cash refund of unutilised excise credit. Where exporters claim only the Customs allocation of All Industry Rate drawback, the prohibition on refund in the MODVAT/CENVAT rules applies solely to refunds of credit attributable to Central Excise or countervailing duty; because CENVAT does not cover Basic Customs Duty, cash refund of unutilised CENVAT credit of Central Excise/countervailing duty on inputs used in exported products is permissible, and the same interpretive position applies under equivalent CENVAT refund provisions, subject to applicable safeguards and conditions.