Gcn Broadband — internet service

Address:

560100

I took internet subscription for 3 months. Every time like almost 75% of the times there is not connectivity. And when we try to call to log a complaint, the call gets blocked showing 'line busy'. Who to approach to get this resolved? Pretty hopeless situation we are put in after taking gcn.
In the last two months already 1 complaint was raised and it was solved and immediately after that there are so many issues with no connectivity.