Cognizant — Pending Offer letter

Address: Pune

Hi, I have cleared all technical interview of cognizant in April and had HR discussion also where they said "Congratulations! You can get your offer letter within a week" but its been more than a month didn't get offer letter and tried calling HR there they said its recruitment team work we don't know about that. Seriously its feel very bad if we gave all our time and effort for some company and at last they don't respond and give what they committed initially.