Unwanted Gift Card Purchase on invoice

Today is Black Friday. I made an Online Apple store purchase of an piPad Pro with $100 gift card reward.

I signed for Apple Pay. The invoice reflects a gift card purchase which I did not want and $100 reduction of price noted in red. I could not remove charge of gift card at check out. The online chat said the charge is made then credited. I now have $100 gift card in my email inbox and a charge for $8.33 a month to pay for a gift card I did not want to purchase. I am Feeling rooked in this force play to purchase a Black Friday deal. No Deal and $100 financed unwanted gift certificate. I conclude it is a forced agreement to get the $100 dollar reduced price you must purchase $100 gift card. Help me understand!