Look you can't download it again online through http://wbjeeb.nic.in however, you may check for http://wbjeeb.in , another site of jee board if there is an option. Else you might have to f irst visit their official website and get their contact information. Then either email them describing about your requirement and ask them for help and wait till they reply. Or you can call their helpline number and directly share your issues with them. Hope they help.
IIT/JEE 2020 Online Preparation
Crack JEE 2020 with JEE Knockout Program, If you Do Not Qualify- Get 100% MONEY BACK