Salary not paid

Hi I worked with a company for 2 years (April 2016-april 2018). Due to some professional reasons I decided to quit the company. I had put in my resignation on 29 March 2018 stating I was ready to serve 2 months notice as per the terms of the contract. The management did not acknowledged my mail till 10th April 2018. On 10th April when I got reply to my mail by my CEO stating that it has been accepted and I would be required to serve only one month's notice instead of two. The mail.also said that my salary for march and April would be given to me as F&F on 10th may 2018. Before leaving the office on 30th I had asked HR for my reliving letter and form 16, which I was told I'd be given later. On 10th may I did not receive my salary and asked the HR to which she replied saying she'll get back to me on it. Since then they have been Farley replying to my mails. Now they have sent a mail saying that by the end of the month the salary will be paid to me after seeing how much is to be paid. On asking about reliving letter, the HR replied saying it comes as part of F&F only so can't be given now. I have a couple of offers I. Hand and to finalise the deal I need to submit my relieving letter. But with the HR neither giving the salary nor the letter, I do not know what to do. Is there a way I can expedite my salary, form 16 and reliving letter process from my ex employer? My CEO is not taking my calls and the HR keeps sending these vague mails not mentioning exact date for money transfer. What can I do? Kindly help.