Byju's — 11&12 SD card

My Son was studying Byju's for last five years. He completed his CBSE 10 Board exams past 3 weeks. His course is K 6-12.He doesn't have 11&12 CBSE SD CARD. I tried to contact the Byju's mentor via help line number [protected].But heard only the recorded voice message the number doesn't exist. Past two I mailed again and again but I didn't get the solution. What should I do for this. Please concern this and solve my problem. Send me the 11&12 CBSE SYLLABUS SD CARD & arrange me a call back segment.