Mary Meza uses phone cards to call her family in the Dominican Republic. But she complains she doesn't always get as much calling time as she expects.

Mary says, "I get really angry because I think it's not fair."

Consumer Reports analyzed more than 130 prepaid phone cards. Most cost just $2 - $5. They look like bargains. But Consumer Reports found lots of problems.

Robert Tiernan with Consumer Reports says "Three quarters of the cards we looked at didn't tell you how much it cost to make a call. You usually never found out until you were on the phone."

And Consumer Reports found the amount of calling time varies tremendously. For example, these cards both cost $2, but this one gave us 200 minutes to call Mexico City. This one, only five minutes.

And there can be lots of fees, which may be listed on the back in tiny type. Those prepaid phone card fees can include a fee for connecting or disconnecting or calling on a cell phone or calling from a pay phone. There can even be a daily maintenance fee.

Bob warns, "The fees can really eat into the value of the cards. These were completely drained before we ever made our international call."

In some cases, Consumer Reports was able to get the fees reversed, but only after calling customer service.

Bob says, "If you frequently make calls overseas, there are better alternatives."

You can use Skype on your computer or smart phone to call overseas for modest rates, which are clearly spelled out on Skype's website.

George Delgado says, ""Skype is phenomenal."

And if, like George Delgado, you and the person you are calling both have Internet, the call can be free.

Consumer Reports says another option for people who regularly call overseas - use an international calling plan through your cell-phone or landline provider. For a small monthly fee, you can get calls for pennies per minute. And unlike many prepaid phone cards, the charges are clearly spelled out.