Cognizant Technology Solutions — Interview status at cognizant

Address: Mumbai City, Maharashtra, 400607

I interviewed at cognizant mumbai powai on 16th july 2016 and cleared all the round and shared the cis form with hr.
After that she is not receiving any calls and not giving me status.
I have even posted query in cognizant official website and mailed few talent acquisition hr's but still i haven't received any response so far.
I have another offer letter and date of joining is 17th aug. so i don't have time wait for the offer letter. i have to take decision as earliest, where i need to go. please help me out in this regard.