I also tried with so many cards but stanacard is good but it also deduct your minutes without connecting which means just hitting the ring only.But it happens sometimes.You should be aware while the ring going on, and  if it goes on for 2 minutes and the call is not received  then you should cut the line yourself.Otherwise it deduct your minutes.And you should try to call again.But you can talk easily without any problem.It's very clear.

Another card is Himtel. It is quite cheap and doesn't deduct your minutes.It gives 60 minutes for $5 in land line and only 50 minutes in cell phone.So it is cheap than stanacard. It is also good and you can talk clearly.

So I suggest you for both but in comparison to stanacard go for himtel and try once.

good luck