How do I reduce the number of licenses on our account?

We have been paying for 7 accounts, and at most have used 6, and are now down to 5. I would like to switch to paying for just 5 licenses to match the number of phones that we have in use.
Also, I have tried twice to call in for assistance, and while the call was "answered", no one spoke to me. I could hear voices in the background and then the call was disconnected. Not impressed with that level of service.