unauthorized charge

My elderly father made an Act Blue contribution in 2015. Two months he called me in a panic with and extremely high credit card bill. He had a 1500 dollar charge! Upon investigating his account, he has regularly received charges of $10, $15, and varying amounts, amounting to hundreds of dollars a year. As a retired man on fixed income, he does not have the wherewithal to sustain these kinds of payments. He had NO IDEA that these charges were being made. When I tried to contact them to halt the charges I went through a maze only to discover there was no phone number no person to talk to. I left an email message that went unanswered. I would happily join a class action lawsuit against this outfit.