At this point you are torturing yourself.
I understand you are thinking (please forgive me for assuming) that if you DON'T take his calls he will walk out of rehab to find out what is going on...because I'm sure he's convinced you that he NEEDS you to find recovery.
He doesn't. He just has to do the work.
and he doens't want to.
He wants to occupy his mind with other matters like the relationship issues that are now present...BECAUSE of the drinking and unacceptable behaviors.
In a way...taking those calls. Getting sucked in...is doing him more harm than good.
I wonder if you were to take one last call. Explain to him that until he shows you that he is in recovery and doing the work...the relationship is over... do not call again. I will not take the calls....
You really are only hurting yourself by talking to him right now.