Appeal

Case: A ltd has purchased a land from B ltd for rs 12cr. In AY 2010-11 , but the agreement was made in Ay 2011-12 and Altd has paid only 10 cr in AY 10-11 and showned as advance made to B ltd. On the other. Side B ltd has show A ltd as debtor in A.Y 10-11 at 12cr. Agreement was made in AY 11-12.. AO on the bases of Bltd accounting, has disclosed 2cr to Altd as undisclosed income and charged sec 69B. To argue against case is there any case law with reference to above case .. On which points A ltd can argue against the charge put on by AO?????? Answer urgent plzzz :)