Threat from employer reg. terminal benefits and experience letter

Dear Sirs I work for an Indian IT company who have sent me on a deputation to UAE and I have been working at client location for more than 4 years. Due to some reasons, client management is forcibly persuading employees from the same Indian IT company to change employment to a UAE based man power consultancy. Due to various let downs in the organization where I am being forced to join, I have refused to choose the option of joining the man power consultancy. The rule is that if one doesn't like to join the UAE based company, he / she can resign from the Indian IT company as the contract with the Indian company is valid only for next 5 months. I have informed my client management through a clear email that I do not choose to join the UAE company and hence they can make necessary arrangements for my replacement. They are now forcing me to stay beyond the contract end period ( more than 5 months) and train the replacements. In this case, they are asking me to shift to the employment of UAE company after the Indian IT company's contract expiry. I have not expressed interest in this and I have informed the client management that I will serve till my Indian company's contract is existing. My notice period is actually only 1 month but I have informed client management before hand so that there is no impact on my resignation. Now the client is threatening me saying if there is any service impact due to my resignation after 5 months, they will ask my Indian IT company to stop my FNF settlement, benefits and experience letter. Can you please advise, as an Indian employee and not have done anything wrong from my side, how I can assure that I receive all my rightful settlements including the experience letter. If the threatening from my client goes to further extent of impacting my salary, how should I handle the situation?