Termination without Final Pay and reimbursement

Dear All respected concerns, I was working with my Ex company since Aug 2016 as senior Manager accounts & Finance. However since January 2017 due to family issues almost for a month i was reporting late to the office however used to complete all the work by waiting till late in the night. But still the HR issued me a memo for my late coming. Again now in April due to my health issue i have asked for a leave of 40 days for my medical treatment however HR and reporting authority refused, as a result after 7th April my health started taking tolls and was not able to report to office from 7th April 2017 to 21st April 2017. I took the reports and the certificate from MD practising doctor and sent it to the reporting authority and HR, however to my surprise i have received the letter of termination dated 27th April 2017 stating that i have been terminated with immediate effect due to absent-ism. I received the same through registered Post. However I was awaiting for my part salary of Jan, Feb 2017 and Full month salary for March and April 2017. They have not paid single amount to me and asking to visit office and do the exit formalities by handing over all gadgets and documents that i have with me. Apart from this i have also done a transaction of Rs.45517/- through my personal credit card for the company on 1st April 2017 but the same is still not reimbursed to me yet and i have been levied late payment charges for the same. Also Note that i have still not being issued the appointment letter from the company. Kindly advise me on the below points 1. Should i visit office and submit my resignation and all the gadgets and ID issued to me? 2. If yes for Point 1, then what if they promise me to pay the same and do not pay after the exit formalities are completed? 3. What if they issue a cheque for my pay and reimbursement and the cheque gets bounce? 4. Do i file a case for additinol charges since the company has issued me termination letter? 5. If i take help of labour court, can i get the charges incurred for the case reimbursed from company only if the result is in my favour? and in what circumstances the same cannot be claimed from the company? 6. Can i also ask for damages for mental harassment from the company because they are paying delayed salary ever since they have hired me. Please answer Thanks & Regards