Let \( f: R \rightarrow R \) be a function defined by \( f(x)=(2+3a)x^{2}+\left(\frac{a+2}{a-1}\right)x+b, \, a\neq 1 \). If \( f(x+y)=f(x)+f(y)+1-\frac{2}{7}xy \), then the value of \( 28\sum_{i=1}^{5} |f(i)| \) is:
\( 715 \)
\( 675 \)
\( 735 \)
\( 545 \)