Refund Question I have (Please Read)

I'm sorry to ask about this but for a few times, I tried refunding a few games I didn't liked, worked as expected and even bought by another one of my siblings and they would deny the refund. I wanted to ask if someone can please tell me Microsofts Policy
on refunding games or send me a link so i can read through. I heard from several people saying that Microsoft will accept 1 refund per calander year but i don't know if its true so i filled up a form for this year (2019) to see if this is true. I will appreciate
someone knowing about this to tell me.

:)