I already figured it out. I don't need to use C(i+1) for my iteration equation for this particular matrix.
All I have to do is proceed with for loop:
for i = 1:n;
C = A*B
[maxC, index] = max (abs(C(:)));
maxC = maxC * sign(C(index))
D = C/maxC % factor out the largest magnitude in matrix C
B = D % this is the new value of B
end
This will result with my expected answers