Tricked me into resigning

This is a bit longer than i expected, please read and then advise. I worked in a PSU company at that time i wanted to do something on my own so i went on a leave for 7-8 months then i received a letter that a disciplinary action has been taken against you because of long absense, so i went back to the comany and asked for the remaining bond amount which i had to pay in case of resigning(i had 3 years contract with that comany from oct 2009-oct 2012 for 3Lakh rupee based on time duration), even after my repeated queries the comany manager did not tell me the amount which i had to pay since it was almost 3 years since my date of joining so i assumed it was somewhere 40-50k which i had to pay,but comany manager didnt tell me how much i had to pay,after i asked to for a meeting then i was confronted by comany manager and my department representative then again i asked them how much it was then they both told me to resign first and only then they will tell me how much money i had to pay for resigning,then i told them that i do not have enough money to pay to pay for bond for that they told me that they will deduct remaining bond amount from my PF, i still insisted that i do not have enough money so tell me how much bond money is still left but they said its a time consuming process to calculate bond money and they will only do it after i resign , for that i asked if i resign and if bond money is too much then can i take back my resignation and resume my duty? for that both replied yes you can withdraw your resignation with 30 days of applying and resume your post if bond amount comes out too much, for these things i accepted to resign based on the condition that i can withdraw my resignation if bond amount is too much. so i resigned, but after many days i i found out that i have to pay 2.7L rupees as bond amount , which was unacceptable so i went to meet the H.R manager but both of them refused to see me, after many attempts my dept representative told me over phone that i had no choice but to pay the bond amount as cheque, i told him this bond amount is too much and i want to withdraw my resignation but he said that i can not wthdraw it since they have already accepted it, for that i asked him that they promised me that i could withdraw it within 30 days, he replied that he doesn't remember any such promise and he told me again that i have to pay 2.7L by cheque and he hung up. so i formally applied for withdrawal of resignation, but again then again i received a letter saying that withdrawal is not possible. then i tried calling my dept representative after many attempts he received my call which i recorded on my mobile in that cann he admited that yes they had told me i could withdraw my resignation. i only have that recording as a proof to what they told me and then reneg on that agreement. please advice me what do i do now? its more than 4 years since that incident. thanks in advance.