Mugg and Bean bad coffee shake

Today was an extremely hot day but I was feeling for coffee. I then went for the alternative choice and had a coffee shake instead because of the hot weather. I am generally pleased with Mugg and Beans coffee however, the coffee shake had no coffee in at all and tasted like an ordinary vanilla shake with powder particles in it which was extremely disappointing for a coffee *****. I asked the lady that assisted me to taste if it was a coffee shake or vanilla shake and she rejected my proposal and asked the Barista to remake the shake. I tasted my second shake and it tasted exactly the same as the first. I've had Mugg and Beans coffee shakes on numerous occasions and enjoyed it thoroughly. I didn't bother taking it further with the employees because they clearly do not know what a coffee shake is suppose to taste like or that is just their standard coffee shake. When I got home I added my own coffee to it to make it taste like a coffee shake... Turns out I make a better coffee shake than Mugg and Bean. Other things I was not happy with was the fact that it tasted and had powder particals in it. It was extremely thick and couldn't suck it out the straw.