Steak 'n Shake

Got a kids size vanilla shake. Was eating it with my straw end as it was too thick to drink through the straw. Noticed dark streaks. Assumed it might be chocolate remnants from using the same mixer, if they still use mixers. Didn't detect a chocolate taste. When I got close to the bottom, it was hard packed about 1/2" with a dark, maybe brown or caramel colored substance. I almost got sick, it was disgusting. It was a Wednesday, Jan. 4 @ 8:35 pm.