I have resigned from my job. The employer has accepted my resignation. But after some days my office laptop came with some issue. So the IT department told me to submit the laptop to the office, so they can repair it. But after one day I got a mail stating that due to a system issue you have to complete the remaining days of the notice period once lockdown gets over. Can they increase my notice period in such an unethical way? And how to handle this situation?