ACT Fibernet — complaining about fraudulent bill and non availability of customer support

This is yash here from chennai. I have received a bill of rs.3024 for my connection whereas i had changed my plan to rs.899/month. I have the confirmation message also for the same. When wanted to know the reason behind the same and tried contacting the customer support, the only response i could get is the network i am trying to reach is busy. I have almost tried calling 20-25 times and got the same response. I want an immediate response on the same or else i would be filing a case against act on the same.
You guys promise of 100 mbps. Have complained about the same also so many times. But again the same story. The maximum speed i get is not more than 30 mbps.
I hope the people handling complaints on this page take it seriously and take some action on it and provide me with a solution if not will meet them directly in the court.