Treatment of reimport goods for processing & re-export-reg.

Dear Experts, We have exported our goods in april 2016 under rebate claim of excise duty. we have received all claims and incentives from the department. Now, due to some quality constraint we have import the same goods (re import for reprocessing and re-export) after paying all custom duty. 1) Whether we can take cenvat credit on such cvd and additional duty on such goods and can treat as a purchase ? 2) Whether we have to reverse excise duty claim and other export incentive received by the department ? 3) Whether we have to book sales return ? Please clarify. Thanks & Regards