Assalamu Alaikum during Christmas, a supermarket offers in their app for free an online advent calendar where you can open a gift each day and receive rewards such as free products, discounts. I used it to get the discounts. Was this haram, or even kufr?

Ustadh AbdulAziz al-Haqqan

Even kufr? We have to take care of waswas and not pay attention to such questions.