Sun Direct — not getting proper service

Address:

Mumbai City, Maharashtra, 400070

We are using sun tv channel for more than 10 years. Now recently we changed the set of box in to hd. But for more than one month we are not getting any channel properly. We complained for more than 3 times. Every time they told, their technicians will come within 48 hours. But still now nobody came. And without solving the problem they sent a sms that your problem solved through phone. What can we do?