Your company has been sitting on payment of your wages............arrears/increment/incentive for a long time. You have a justified reason to agitate.
It is felt that since you are in pvt. sector you are burdened with the speculations. You know your employer better than anyone else. In such situations employee should become smart and apply skills.
It is reiterated that it shall be appropriate to approach a competent and experienced service lawyer with all records and give inputs in person, and let your lawyer structure all communication you may submit to the company. An expert lawyer can handle the situation.
You must represent to your next employer in writing under acknowledgment 9 even if by email) that your current employer may not issue acceptance of resignation, experience/service certificate, relieving letter, FNF statement, etc and you can provide only copy of resignation letter and POD and if acceptable you may be allowed to join. In the absence of an understanding your next employer may press for the documents after some time. Your next employer can accommodate you if he is willing.