Reliance Bigtv — new connection not installed yet

I applied for a new connection in march but it has been more than 4 months now and no connection has been installed yet. Whenever i contact their customer support they always provide a new deadline, this sort of behaviour was not expected from such a big company. Even when i contacted for the refund there was no reply from their refund team. My booking id is 14539297. Please help me out with this issue.