Brandy Norwood is being dragged to court over a $45,000 ring she was supposed to wear at the American Music Awards ... a ring that's allegedly gone missing. Brandy and her stylist, Ashley Sean Thomas, are being sued by Elle B. Mambetov, a fashion designer and Beverly Hills store owner. In the lawsuit, obtained by TMZ, Mambetov claims Brandy's stylist approached her last year about borrowing jewelry and clothes for the singer to wear at the November Awards show ... and the designer let them borrow some outfits and a Dreamboule Big Bang Diamond Ring. Brandy and her stylist allegedly never returned the ring ... and the ... (full story)