just dial *8186*1# as many time as possible
if you get "Your request is being processed please wait for a confirmation SMS" thats when
you should keep on dialing as many times as possible
but if you get "sorry operation failed" then dnt stress your self.
then sit back and wait for this reply:
Dear customer, Your monthly
data bonus is 4096 MB
Valid till 2016-05-21 00:00.
Dial *200# to purchase data bundle
In some case u will not get a confirmation SMS, jst dial *228# if you are lucky u will see your 4gb. jst got now.
see image below and thats all