Sometimes your printer won’t print in black and white if a color is out because it uses all of the colors to create a deeper black. Depends on the model though.
And some of them use yellow as a lubricant because yellow toner has a consistency close to water.
Also, please do not copy money or your butt. Trust me.
When I’m dealing with ISP or phone customer service, I always ask for the cancelation department. They are motivated to keep customers so sometimes they’ll throw in a coupon, especially if you treat them like a human.