Verizon and AT&T haven't offered
unlimited plans to
new customers for years, but existing subscribers are seeing the cost of their grandfathered
unlimited plans rising: Verizon hiked the price for its
unlimited data
pack by $ 20 to $ 50 a month, while AT&T announced
plans to bump the monthly fee for
unlimited data from $ 30 to $ 35 in early 2016.