Capgemini — capgemini not releasing offer letter

Address: Pune, Maharashtra

I am done with all my rounds, discussion with hr, finalized my package, submitted all documents but still i haven't got any update from hr regarding my offer letter as its been 2 months after discussion with hr. My interview took place in december through walk-in.
I communicated with the hr via mails but always received the same response that the process is in progress.
I guess this is bit unprofessional and not expected out of such a huge company like capgemini. Can someone please help in letting them know that they shouldn't delay so much in providing the offer-letters. It's really maligning their brand image.