I can reply to your message when I have the time for it and carry on.

I can delay the reply if it’s not urgent.

You can spend time actually writing what you want from me, so I can read it, and give you full answer. We both can then actually recall the conversation because it’s saved.

And for people saying you can deny the calls - you can, and then you deal with narcissistic assholes having beef with you for doing so.