Zong offers free calling details (Calls+SMS List) for last 30 days to its Prepaid and Postpaid Customers.
Just visit this Website and give your mobile number, name and email address.
You will receive your password through sms on your zong mobile number.
When you receive your password, go to this website address:
Enter your mobile number in this format 923131234567 and your password. You will be asked that details of how much days do you want, select the days and you will be displayed with the outgoing calls and sms details. You may change your password later on.
This service is totally free of charge. Zong is the only mobile operator in Pakistan which gives you details online and above all it is totally free. SAY IT ALL