Mobikwik cashback validity

How does mobikwik determine cashback validity?
For example : happilo voucher code validity is 1 month. If I add a 200 rupee code on 10th and another 200 rupee code on 30th, and then make a transaction of Rs 200. So what will be the validity of remaining Rs 200 ? 10 days or 1 month ? I’m asking this question because while making transactions, mobikwik deducts the added funds first instead of cash back fund. So similarly it can also deduct that cashback first, which has longer validity. Is it so ?