Britney Spears has written an angry poem about her mother, in which she claims she has "no mom".The 'Toxic' singer, who was believed to have hand-delivered legal papers to mother Lynne last month, is alleged to have given her a page of hate-filled verse. A source told America's Star magazine: "In the poem, titled 'Dear Mama', she wrote that she didn't have a mom anymore and she couldn't imagine a mother doing what she did to her child."Britney gave the poem to her mom and said, 'Here Momma, I just wanted to see your face.'"Then she got into her car and drove off. Lynne went into the trailer and broke down in tears."The 25-year-old visited Lynne on the set of her younger sister, Jamie Lynn's TV show, 'Zoey 101', and also allegedly handed Lynne a legal order banning her from seeing her grandsons while she is on any form of medication.Britney reportedly hired a private investigator who recorded phone calls between Lynne and the singer's estranged husband Kevin Federline, arranging visits with 22-month-old Sean Preston and 10-month-old Jayden James.In one conversation, Lynne is said to arrange to meet Kevin and the boys,saying: "I have to be careful that Britney doesn't find out!"In another call, Kevin assures Lynne his court battle against Britney for custody of their sons is going well.The source said: "Kevin told Lynne that he had everything under control. He was just going to let Britney hang herself in court."