Hope, I'm not being judgemental here just writing what I see.
I can see the validity of both opinions: pick up the phone or not.
However what I also see is that by NOT picking up the phone after sending a message that could be construed as you making an attempt to get a reaction out of your H that he might feel you are playing games with him and don't actually mean what you say in the text.
Just my two pennies
Me 43 XH 45 M 2.7.88 Divorce 7.10.09 Kids D20,S17 & D15