No, we don't take clients like that.
No, that's not part of what we offer.
No, that market is too hard for us to service properly.
No, I won't bend on this principle.
No, I'm sorry, I won't be able to have lunch with you.
No, that's not good enough. Will you please do it again?
No, I'm not willing to lose my focus, and no, I'm not willing to compromise.