In order to use AdMob, publishers must be comply with Google Play Policies. The Google Play Policy Team reserves the right to disable your app if found to violate Google Play policies. If your app is found to violate any Google Play policy and offending then app has been removed from the Google Play Store, ad serving in AdMob will also be disabled.
For details about the violation, please review the email notification that the Google Play policy team sends to you. If you do not see this email, try searching the inbox of the email address associated with your Google Play / AdMob account to find mail from firstname.lastname@example.org. Check the email account spam filter to ensure that mail is not accidentally flagged as spam.
After correcting the violation, you must file an appeal process through a designated contact form; email replies back to the original notifications will not be reviewed. If your app is removed by the Google Play policy team, submit a Google Play policy appeal.
If your Google Play policy team re-enables your app, continue to submit an AdMob policy appeal. The AdMob Policy team will review your app and decide whether ad serving is reactivated.