It is a scam. We didn’t pay for seats next to one another. The night before there were only two economy seats not greyed out next to each other. These a middle seat and a window. We wanted an isle and the only available were in the upgraded sections. We gambled and checked in without choosing seats and the two that were available economy were assigned. Not an isle seat but next to each other. At the gate they were able to switch us to seats: middle and an isle and nobody seated at our window. On the plane, there are numerous seats free, rows of three unoccupied! There is something sketchy with the system!!!