Genpact Manager interview questions

Interview process was pretty smooth and easy. There were 2 rounds one with the hiring manager and one with the client and 3 rounds of HR discussions initially. After the client round HR has called and informed that I am selected and discussed about the pay and benefits after all these discussions when HR has to release the offer letter she said that there is an anti poaching clause and she cannot hire me for this process which I have been interviewed for

All my rounds were done, went into Negotiation with HR and we both finalised on an amount, she told me that offer letter will be rolled out in next 2 days but it was never rolled out. Tried reaching out to their team but nobody responded.