Company diens to give experience letter

I have work in IT company for last 7.5 year very dedicated and honestly, but in COVID company did not give my salary so I have resigned from the company but i got call my manager and said that we are increasing your salary and giving promotion to you so revert your resignation i believed on him and revert my resignation. than company send me salary increase letter on email and ask to give one year assurance to work in company i gave assurance on mail but after that company did not give my pending salary after 7 months even i asked many times but one day they gave my pending salary and i have again put my resignation but company dines my resignation letter and said that you are in commitment period so you can't resigne. But thay Stop my salary when I asked why my salary stop then they told you have resigned so we can not give salary so after a4 month without salary and 3 month notice as per my appointment letter I left the company. After some time I askd to company to give my experience letter but they are not giving then i have sent a legal notice they also dined my notice and send my other notice to me and asking for they salary of commited month. I have not commitment anything but give assurance on mail but company is not considered my request and they hold my money and experience letter Please guide me.