Not giving full and final settlement amount and relieving letter

Hi experts, I had resigned my job on 2nd July thru mail to HR manager and copied to director. I had discussion with HR why are you resigning the job what happened, so I told that director is giving bad words while speaking with me and insulting on mail copied to the customer. So I don't want to work. On 30th I got call from same HR manager told me to handover the company property laptop and mobile to the reporting office. And told me I will call you for exit interview, but still I had not received any calls for exit interview. And I handover the company property with perfect working condition. Then on 1st Aug I joined the new company and after 45days. I asked for my full and final settlement. The same HR manager is telling you are relived from this company yet. Now they are sending letter to my new company that I had joined without relieving from their company. And treathening to take legal action against me. That one of our client was introduced by me has not paid our outstanding.