I have a BA degree in computer science with a few years of professional experience. A few month ago I started working for a humanitarian NGO (with US-American origins) which is active in some lesser developed countries. For two weeks, I am now in the designated country somewhere in Africa. The position I have signed up for is called "head of the IT department". In the organization, there is one guy who I am officially the supervisor of. My supervisor has the title "director of the technical services". That means, he is also the supervisor e.g. of the "maintenance manager" and the "logistics manager". My supervisor is not around here physically. He is in his home-country for some health issues since a few month and is very likely not to return anymore, so we are communicating via internet.
Now my supervisor has next to him (in the organization) a guy being the "technical assistant". Let's call him "Joe". Joe is a retired computer scientist working as a volunteer. Joe is doing IT projects here like upgrading and maintaining the network and is referring directly to my supervisor.
Actually I do find that irritating, because if I am supposed to be the "head of the IT department", I think he should work with me, and not directly with my not specifically IT-related supervisor. I have already made the request to my supervisor that Joe should be in the organization as my technical assistant. He simply refused. The thing is: I am quite new here, but Joe is here around for about six years and has gained a lot of trust.
Additionally, Joe does behave like THE BIG BOSS here (as far as IT goes). He is giving me orders all the time. Twice I dared to question his (non IT-related) orders and he shouted at me: "WE WILL NOT DISCUSS THAT! YOU WILL JUST DO AS I TOLD YOU". When I have some other opinions on IT-related topics, he will just tell me for half an hour why his way of doing that is the only correct one. There is no way that he would ever accept any other opinion or point of view than just his own.
I have tried to explain my supervisor last week in a rather careful manner that Joe seems not to be aware of me being supposed to be the "head of the IT department". He apologised and told me, maybe he has forgotten to give him the memo, so he will do that right after our (virtual) meeting. Of course Joe is in fact completely aware of that for almost two years now. (I was in touch with this NGO and Joe for some years now putting in a lot of effort until finally it became possible for me to get here).
Today evening (almost a week later) Joe has given me a quite elaborate schedule for the next week of what I have to do at what time. (Pretty much exactly in the same manner as you were given a schedule by your teacher in the elementary school). As I said, my job description I have signed up for is called "head of the IT department". Even though this schedule would be pretty much an insult for any adult.
Joe does clearly not mean this as an insult. Actually he is very friendly (as long as everything goes as he wants) and he just thinks this is the most helpful thing he can do for me and certainly that I should be very thankful for all the effort he is putting in. He actually did helped me a lot with some visa issues while I was trying to get here, lent me money as long as I was not able to get some local money for myself, spending a beer after work, etc. pp.. This does give me the feeling of being in his debts, which makes the situation for me even more difficult.
What would you recommend me to do in this situation?
EDIT:
I had some talks with my supervisor since. He understood my situation, apologized for not having overthinking the situation enough in before and may have not communicated it well to Joe, too. Also he had some talk with Joe.
Since a few days Joe is clearly making an effort to not command me around but sell it as proposals. As his proposals do make sense and he is a lot more experienced with the overall situation here I am very happy with how the situation has evolved since.
I thank you for your answers. Some of you gave me thoughts that made me rethink some aspects and communicating certain aspects better to my supervisor to avoid some of the misunderstandings I could see in your replies. It is difficult for me to mark one answer as the correct one though, because by itself all responses were reasonable and had good points for the way I tried to describe the initial problem.