You Broadband - Service not provided and refund not processed

I have requested for a new broadband connection and paid for the connection online as the you broadband customer executive promised me that the installation will happen in * days. After the payment, I was told that the service executive isn't available, so it's getting delayed. After waiting for a couple of weeks, I have asked for a refund. Since then I have been calling the customer care multiple times and all they say is our backend team will look into it. I even wrote a mail to the nodal officer and nothing happened. It's been *.* months and I have contacted them several times but they are not processing my refund.