How to gain Eligibility of airtel weekend 1GB for #100

I saw this somewhere, though my sims are eligible but i want you guys that are losing this cheat to do it quick because i can see it as a loophole.
To get the eligibility, just dial *475#, until you receive a confirmation alert, after that then dial *474*1# and you will see that it will alert you that you have insufficient balance but make sure your balance is EMPTY before you try it.