I've recently joined a company. I've found out that the work promised to me during the interview is completely different from what is assigned to me. I've talked to my supervisor and told him that I would like to leave as soon as possible. My supervisor responded as follows: "I've talked to the CTO, and your notice period will be 2 weeks." The next working day, I received an email from HR mentioning that the notice period is 3 months as per the agreement. Now they are threatening to take legal action. They are also saying that they'll ruin my career prospects by complaining against me at the U.S. embassy/consulate. They aren't even open to payment of salary for the notice period. How should I proceed? Please advise.