Purchase Gift Cards At A Discount

I had over $100 accumulated in cash back bonuses based on my credit card purchases. In the past they’d mail a check whenever you called and asked for the cash back. I called today and they said I can have a gift card to Macy’s or Bed Bath and Beyond or a Discover gift card unless I give them all of my checking account info for them to make an automatic deposit. Due to identity theft I never give strangers access to make automatic deposits into my checking account. Isn’t it illegal for them not to offer an option to mail the actual cash back to me especially when they advertise it? They used to mail checks in the past but they said they changed their policy. Is that legal for them to withold the money and offer me gift cards instead (which they get for a discount from the stores at half the value so it’s like they’re only out of pocket half the cost). I’m so pist I want my cash back! Discover sucks.