Corporate Sales Office/Administration or Directorate? Which is best name?

Corporate Sales Office/Administration or Directorate? Which is the best name?
Help me to choose the best name for the company division, please! :-(

This company division deals in corporate sales (Kazakh postal company).

What does the company division do? Directorate is not common.

not a teacher

If it is a division, then Corporate Sales Division makes the most sense to me.