Accused of harassing a 14-year-old with robocalls to her cellphone in an attempt to collect on her mother’s credit card debt, Credit One Bank argued that the teenager, A.D., was bound by an arbitration clause in its agreement with her mom, Judith Serrano. This argument was based on the “direct benefits estoppel” theory and a single credit card transaction involving the purchase of smoothies in a shopping mall.Credit One’s computer system apparently targeted A.D. for robocalls because Serrano had …