Cognizant — offer letter not released (technology :teradata)

Address: Cognizant, Bagmane Tech park, Bangalore, Karnataka, 560093

I have attended interview on 23rd february for teradata technology in bangalore. I also completed filling live interview form on march 4th. I was informed that i will get offer letter on 12th march. But i have not received any offer letter yet. I got call in june for client round and cleared (Teliphonic) that round as well. After that on july 10th, i got call saying like my offer letter is going for business approval and i will be receiving my offer letter as soon as possible. But i have not yet received.