Act Fibernet Bangalore - Refund for Months not used

I have paid for a * month broad subscription (March to May ****). I had asked the sales person to whether a monthly invoice will be provided with instead of the combined invoice for which he said yes. Beginning March **** I called up the support team and asked for monthly invoice to be generated but they said it is not possible as I have paid for a * month prepaid service. After going back and forth with the support team they finally gave a separate invoice for March **** and told be to call back end of March to get the April bill. When i called them back they again provide the same response of not able to provide the monthly invoice. I registered multiple Service Request tickets with them but they kept closing my tickets without prior permission or asking me whether the issue was resolved or not. I send emails to their nodal officer but again with multiple back and forth there was no resolution. So finally I decided that to close the connection as I was tired for the attitude the support team was providing with any resolution. I requested them with a disconnection request and also asked for a refund for the the unused months (April, May ****), they said they cannot provide a refund for the same according to their terms and conditions. No where in their invoice does it mention that refunds will not be provided in case of termination of service without use. They have also disregarded my disconnection request saying I was satisfied with my resolution of complaint! I have attached the original invoice of *months, email trial of exchanges to nodal officer and a partial list of SR's I have raised.