Nokia x2-01
Poor battery back up

Dear sir,

i bought a nokia x2-01 one month ago, iam getting very very poor battery back up when using net, every time after being fully charge the battery goes empty within 3to 4 hours of net using if net is not used then it gives long back up of 3 days

1.is this the problem of battery?

2.is this the problem of the set?

Its make me very dissapointed for nokia