Hathway Hyderabad - Internet connection terminated due to their own wrong records

I have initially subscribed for the super speed ***mbps internet service on Feb *rd **** which is for * months. Then the next day the hathway executive informed us that the specific high speed service is not available and I can opt for general service which is for * months in total if I pay INR *,*** more. I have paid the differential and opted for the general service. And here comes the issue, Hathway team can't update their own internal records to reflect this and has terminated internet services for the past * days. There is no response for the emails sent to their help desk. Moreover I am getting minimum * to * calls from hathway asking me to renew the subscription which is ridiculous.
They were unable to even to give me valid tax invoice for a period of ** days and they won't take any responsibility for the loss or distress caused.