Isi and Mar met while Marissa was studying in Ghana during 2009.
Applied for K-1 in Jan 2010.
Mar's Pareents and her traveled to Ghana in July 2010 for them to meet him.
Isi arrived December 2010- Accra was not too bad- if prepared
AOS Complete- June 2011 with no interview.
ROC submitted April 1, 2013....approved with no interview on 7/31/13
N-400 submitted Aug 1, 2016
they ALL do go to NVC. As others pointed out the letters are not always clear. Its stops at NVC- if they dont have record you have to wait till you get the number from them. Accra will not speak to you without the ACC number you get from NVC. So keep trying. best of luck