We understand it is very easy to be confused in this way.
First, this card has 10% surcharge as we advertised; Second, this card's remaining balance is always reported in its local rate, even if you call from toll free number.
For example, in the very begining, you will hear you have more than 24 hours when you call from toll free number. But actually you did not have 24 hours. You can only have 840 minutes (before 10% surcharge) if you calling from toll free number. For this reason, you will always hear the minutes are overcharged.
Another example, you called 10 minutes from toll free number, the total cost for you is 10*(1+10%) * 2.7 = 30 cents. Because the remaining minutes is reported by local rate, so your minutes will be deducted as 30/1.6 = 19 minutes. That's why a 10-minute call would be deducted as 19 minutes.
For calling from toll free number to China, your card should be able to have 840*0.9 = 756 minutes. You cannot have 22 hours or 24 hours. We hope it is a little bit clear for you. If not, please contact us and we can provide more explanation.