Prizewinner

Hello Everyone,
I was a member on this site 2 1/2 years ago and you guys were a great help. Now I'm back with a whole new set of problems.
Background: My partner is an opiate addict (pills). I am 50 and he is almost 25 and we have been together for almost four years. Yes, we are a gay couple (please, no flaming as I can't deal with it right now.)
So 2 1/2 years ago I had my own intervention and kicked him out to make him hit rock bottom. He is Native American and receives healthcare and treatment for free. Two years ago his doctor put him on Suboxone and now my partner and his doctor both agree it is time for him to come off of it. In the meantime, he has been going to college and has made the dean's list two out of four semesters. So he IS a really smart guy and loves me more than any other partner ever has.
Well, two weeks ago my partner tried to detox himself at home and it was a disaster. He went to his doctor and he wrote him a rx for one week to slowly taper him off with decreased doses each day and also arranged for my partner to enter a facility for 30 days. This particular one is has a great reputation for detoxing Suboxone patients. He took his last pill Fri. morning before we left for the four hour drive to the facility.
Now he has nearly or already used up the calling card I bought for him because he started telling me he wants to come home after he has been there for only 24 hours! I feel as if he needs to stay there the whole 30 days. And that is probably going to make me look like the biggest a**hole in the world in his eyes. I feel that this is a huge "gift" as they say on Intervention and he shouldn't let down the people who worked so hard to make this happen. I just don't understand this turn around in his behavior because he was so pumped up about going and was excited all the way there.
I know for sure the half-life of the Suboxone will run out tomorrow or Tuesday and then his withdrawals will begin in full force. Another thing he has been saying is that he wants to come home right after detox and I don't think that's right either. He hates where he is because it is an older, renovated house that he says stinks. He's complaining that one of his roommates has severe body oder. He says he is so much further along than the rest of the patients are in their recovery process. He doesn't like the rules as in being told where he can and can't go and when to do things. He feels that because he went there voluntarily that he can leave anytime he wants unlike the others who are there at the facility by court order. I finally told him he's an addict and all of this is addict talk and I don't want to hear it anymore and if it is so bad, go and complain to his counselor about it because I can't do anything four hours away.
All day yesterday I was in huge codependency mode and spent my entire day off of work chain smoking and acting like a maniac because I never expected this would happen.
So what do I say when he calls begging to come home? And I want to write him a letter, but what do I write?
Please help me out with some advice as I really don't know what to do. Thanks for reading, I really appreciate your valuable time!