Videocon Industries — signal not available problem with some channels

I am facing issues of signal not available on some channels. I called the customer service and they send their engineer to fix. He charged 450 for changing lnb. But on next day the same problem arises again. I again call customer service and registered a complaint. After that the same boy (Their engineer) called me said that he will come in next morning. But he didn't came for next 4 days. So i called again to customer service and they said that their system showed that problem is resolved by engineer. But this was not true. Their engineer even without visiting to resolve the problem marked the problem resolved. He do that because videocon has policies for no service charges till 30 after once visit. He think he will not get money so he didn't visited and marked as resolved.
Videocon just resolve my issue as soon as possible.
And i am not supposed to give to money for a mistake that was not mine. If some channels shows signals not available than its your mistake. You can not charge for that.