Change the version code to update on google play (on windows)

i am trying to update my app in google play with a new signed APK.
(i am on windows and run jarsign und zipalign from the command line)

this doesn’t work, i get the error-message:
“You need to use a different version code for your APK because you already have one with version code 18.”

i added a line in mobile-config.js{
version: “0.0.2”

but it seems to have no effect and i really don’t know where the ‘18’ comes from.

how can i change the version code?

any help is highly appreciated, thanks in advance.