Response from Instarem :
"Thank you for using Amaze.
If the rebate is given upfront during the payment at the merchant where for example, the cashier has to verify the type of card, or if there is a check on the Card Type at the terminal, then the rebate by the linked card issuer is not applicable.
However if the rebate is applicable post transactions, example rebate is credited on a monthly basis, then the rebate will most likely be applicable.
Request you to please check with your bank if the rebate is applicable."
Instarem in above response says if its post transaction rebate, it should be applicable.
Whereas it did not.
In my opinion, where you have a store discount combined with an everyday rebate - this scenario might not work.