Resignation from psu bank

Hello sir i have been working with a public sector bank as head cashier from past 6 years and i got selected in state government job. the state government didn't gave me any extension in joining and required me to join immediately and put immediate resignation in bank via email so i did accordingly and put my resignation and also in my resignation letter i mentioned that "since i am unable to serve the bank for 1 month notice period so in accordance with service rules para 522 clause 3 of sastry award – i undertake to pay the bank full one month’s gross pay and allowances as may be calculated by the bank in lieu of serving notice period and authorise the bank to debit the same from my saving account" and then on the same day of submitting my resignation i joined state government job but now my branch manager is asking me to join for some days, i have not disclosed to bank that i have been selected in state government and joined the same, i have said that i am giving resignation on personal grounds. can bank take any action against me ?