My clients will often ask me something along the lines of the following: "I'm not happy with how this project is going. Should I say something to the vendor?"

My answer is always the same, regardless of circumstance: Yes! Say something!

You never want your vendor to say to you "I had no idea you weren't happy!"

So if you're not happy about something, tell them! And if you're really angry (some of my clients say "pissed"), tell them that, too.

Speaking up never hurts, but not speaking could be detrimental to the entire project. So say something.