2001 Malibu air conditioner Control Knob

One of the knobs for the air conditioner is busted at the point where it attaches to the peg. The three dials are interchangeable so I can use one of them when needed but I’d like to get it replaced. Does anyone have a spare or know where I can get a replacement? Any help would be appreciated.

Most auto parts stores carry a line of parts labeled "Help" and they offer a package of assorted knobs.