Shinmaikeru

I have a similar problem with newly-bought, used X-T30ii. I have the front dial set to switch between aperture and ISO, but regardless of which I am trying to change, turning the dial to the right increases values, but turning to the left decreases and increases at random. The dial must be faulty. I am trying to lower the ISO, but turning the dial left decreases and increases unexpectedly. The camera is unusable in this state. Any solutions?