It is annoying to write down everything, but when PHB gets off the phone with you, they immediately start morphing everything that was said into their version of what they think you said. If you don't do this, you will find that you over-committed even when you didn't and you will hear all sorts of things that everyone else thinks that you promised.
At the end of each call COVER YOUR ASS. Eventually, if you are lucky, they will stop calling you altogether and will simply START with email, since you aren't letting them get away with the famous "I thought you understood what we discussed" reality bending mechanism. You probably won't have to re-forward it PHB when they lose their mind in 3 weeks, but if you do, you will have it.
To: PHB
cc:team
June 2015 Release
Thanks for talking this through with me, I will go forward with A, B, and C as discussed and I appreciate that you agreed to delay D, E, F until after the milestone build is stable for the June 2015 release.