Fell in overcharging customers for more than what they are signed up for.

I was signed up for a Telkom contract paying 319 they started billing me R800 when I asked them to stop they told me it would take one month but I still need to pay the 800. The second month they did the same and and kept making excuses and they are adamant that I need keep paying. What ******* so *********, dishonest and a money making ******* scheme