If im paying for something and for example i use my microsoft balance and my card to pay...

Yes, you can refund it. If the refund is approved, the funds will go back to whatever was used to pay for the content. So if say a purchase was 50-50 it will be refunded 50-50.

Yes I get that option. I can either pay with my bank card or Microsoft balance. Hence I payed for destiny with my bank card first time because it wouldn't let me pay with my Microsoft balance.

In responce to Vernierslake, I was trying to use a prepaid mastercard to pay off my balance. Not a pre paid membership card. I have since called microsoft in order to address the issue, And was told I have to use a Credit card to pay off my balance, not
a pre paid. Thanks for the help.

Does it give you an option to change the way you pay because when I pay I can select to use my card or Microsoft balance

Im from brazil, im trying to get 5k v-bucks, no i redeemed the gift card around 6 hours ago, it show the balance when i go to microsoft website.

But i dont know how to pay using microsoft balance in xbox store!!!