At&t had a promotion last February, where if you text yes to 11113020 they would apply 1,000 free rollover minutes to your account. I tried it and it actually worked. Well according to Marlee on our facebook, the promotion is back. Just text yes to 11113020 and it looks like At&t confirmed this on their facebook.
Image Credit: At&t ; Thanks Marlee & swtvtboi2