A missing St. John's student was found alive and was reunited with her family Monday after admitting she ran away rather than tell them she was expelled from school. Erica Desai,19, called 911 Monday morning from a pay phone at Stillwell and Avenue B, claiming she didn't know where she was. Desai said she had been abducted, but after further questioning by police she admitted to running away. Desai had been missing since Jan. 20 when a cousin dropped her off at her dorm near Union Turnpike and Utopia Parkway in Queens. Police said that university officials told them that Desai, a freshman, was expelled after being accused of using someone else's credit card. Surveillance cameras caught an unidentified man and woman using Desai's debit card at a Bank of America ATM at 44th Street and 6th Avenue in Manhattan on Jan. 21. Desai had also posted online messages saying she wanted to run away. Desai left the 107th precinct with her family on Monday night. She is not expected to face any charges.