what about zong sms

here is a very cheap trick..to avail sms service free...
e.g if u hav rs 10 is ur zong account.....
so u can use ur pakage 3 time with only rs 10..
how??
listn.... fst of all u shld type sub and send to 700..
4.77 rs shld b charged,,
n thenn before 12 am.type unsubscribe n send to 700...now u r unsubcribed...
n thn again type sub n send to 700 after 12 am..now u r subscribe..n use 500 sms..n thn wait until 12 am..after 12 am u can send also 500 sms totalyy free..nt write unsubcribe after 2nd activitaion.......