I quit my job today which I joined 6 months back. I was "highly-recommended" for this job by some senior executives of the company with whom I had worked before. (Same company but several years back and different office in a different country). These executives from main office are not involved in offshore regional office or know the management personally. They just sent their strong recommendation. Because of this recommendation, my interview was short and smooth. I loved the culture and people of previous office and hence I accepted this one.
However, I could not survive here for long because the job did not turn out anywhere close to what I was promised during the interview(Pay was good but my role and team were changed significantly). I had several disagreements with the management of this office over last 6 months on my role. Finally I decided to leave.
I left in good terms and I made my reasons clear in as professional way I can during exit interview. Now I am not sure how to tell this to the people who recommended me. I feel that I owe them an explanation because they vouched for me. At the same time I cannot explain why I left without ranting or complaining. They have no context on what I was offered, what I was expecting and what happened here.
So my question is how do I communicate to the people who recommended me without any indication of blame/complains or any kind of ranting? Should I apologize to them at all? (Although I do not think I did anything wrong and the local management messed up). I just want to maintain relationship with them professionally without whining about events from past.