BSNL Broadband — breakdown of broadband

my broad band is breakdown frequently.i have complained for several time though i dont get any response from the service provider. every time i make complain nobody want to accept complain. every time they give me new number to contact. i collect more than 10 number. i had tried on all. still i am suffering from the problem. i m helpless that nobody is there to give solution. so kindly assist me how to reach to solution.