The hidden costs of Calling cards

You may be aware of the many choices you have when buying a calling card. However, have you considered the truthfulness of the claims that some companies will make in order to get a competitive edge? Are you aware of the tricks that are played and the hidden charges that are made? The minutes that a calling card will offer may look good but did you know that even if you were to make one continuous call, then most companies would steal between 10% and %20 of those minutes. They call this "fluctuation". Then there are also other charges to be taken into account;