A customer orders a hot chocolate... Decides to shake about half a shaker of cinnamon on top of it before coming back to complain she put too much on and doesn't want cinnamon.

Sometimes too much comes out of the shaker than expected or the lid might come off if another customer unscrews it...

No, I watched this customer frantically shake on industrial amounts... I'm guessing she thought it was cocoa powder.

I remade the drink, customer didn't learn their lesson. But this time skipped the condiment bar.

It isn't rare for customers to think the shakers are exclusively for their own personal use rather than shared amongst other customers too. I suppose when you are paying those prices, it is just getting your moneys worth!

Top tip: Double check what the shaker is before using it.

Nobody needs to redo your drink so you get a second chance of sprinkling condiments on top of it; so don't assume all baristas and all coffee shops would remake a drink when it is the customers error.