LOL Antoine… I don’t blame you one bit 
I have learned that I have to accept some calls on my cell coming from “unknown” and “withheld”, but as a general rule I will not answer unless I can identify the caller.
I will especially not answer when a call comes in at the wrong time of day UNLESS I can identify the caller. And then they better have a damn good excuse.
In the four years I have been doing this, I have not had to take many calls, fortunately… I generally insist on email so that I have a copy of what was discussed. Outside of that, about 95% of calls MUST be scheduled with me if they want me to take the call. And I don’t ever publish my home phone number, besides which if they call they will always get a busy signal
I can be a people person but not to the extent of making myself available to take calls at all hours. For the most part I’m happy to do my negotiations by email… and anyone who doesn’t answer my email immediately just gets shuffled down the priority list
Operators, if you MUST call, at least have the courtesy of arranging a time in advance. This is an international business – not all of us keep the same hours.