jaidevp: Hi it's likely the issue you are seeing is due to there being no single dominant cell (signal) within your home.
This means the phone will have a tendency to switch between the sites and as you've notice this can have an effect on battery life.
Unfortunately there isn't too much that can be done about this without affecting the neighboring areas.  You can log a fault with our helpdesk to get the issue checked to make sure it's not something else, if anything they (helpdesk) can put feedback into our coverage tool so the issue is highlighted when reported on.

^^ What he said, he's telling the truth, I've confirmed.

Ah ok. Thanks for your help jaidevp and micahelmurphy. I will log the fault and see what comes of it. Nothing else I can do to ease the problem at least (except painting the walls with anti-emf paint and knocking down the walls)?

A big fat repeater system locked on to the tower you want signal from? Of course you'll probably knock out everyone else's signal in the process, and it may be short lived as the RF investigator comes knocking at your door.

Your scenario is very common though and it just the way it is. Best option is finding a good signal spot in the house to leave your phone most of the time.