In e-commerce platform, if you use certain debit cards, you will get a cashback or additional discount as a reward on your orders, is this permissible? The debit card is issued by an islamic bank. And would the ruling be different if it's a credit card?

Ustadh AbdulAziz al-Haqqan

You are asking a very general question without more details. Generally speaking, in regards to using a certain bank card without involving anything that is forbidden, getting certain discounts because of that is allowed.