A curve $C$ has equation $y=\frac{a x+b}{c x-2}$, where $a, b$ and $c$ are constants. It is given that $C$ passes through the points with coordinates $(1,5)$ and $(-8,0.5)$. The curve $C$ is translated 1 unit in the positive $x$-direction. The new curve passes through the point with coordinates $(0,-0.2)$. Find the values of $a, b$ and $c$.