Does Anyone Know Where I Can Get A Decent And Honest Prepaid Calling Card For My Aunt?

She just bought a 600 minute calling card, and it said she only had 82 minutes left when she had only talked for 37. I called customer service and they said it was a 5:1 ratio. For every one minute you use the calling card in state, you are charged five minutes. So, if you divide 600 by 5, you get 120 minutes of actually talking time. Can anyone guide me in the right direction. I am so furious she got ripped off. I cannot even sleep. I am wide awake after a long day at work, and I just want to get some answers.
Thanks so much!!!!!

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