I had a bansai and I killed it after 6m, got another and that lasted ~6weeks.
This was mainly due to an extremely drafty flat.
I seem to remeber being advised (at PoS) that it needs watering weekly and feeding monthly.
If it smells a bit it sounds like the roots may have started rotting.
Have you repotted it at all?
It might have outgrown its pot.
I had a bansai and I killed it after 6m, got another and that lasted ~6weeks.
This was mainly due to an extremely drafty flat.
I seem to remeber being advised (at PoS) that it needs watering weekly and feeding monthly.
If it smells a bit it sounds like the roots may have started rotting.
Have you repotted it at all?
It might have outgrown its pot.