How can I claim Apple Gift Card with new iPhone 14 purchase?

I show this advertise on apple website on Dec 3 . it promised $75 gift card. But when I purchased iPhone 14 on payment plan , agent refuse to give gift card. I wrote certified letter to Apple customer service but they simply referred me to this community. Apple is extremely large company and for them to play this game is terrible. No one at apple listen. I feel terrible. Anyone can help??

[Re-Titled by Moderator]