Now that you have received the email and know that it is a mistake, you will need to prepare all the evidence that in favour of you and make an appeal to Google, however chances may be quite low that you get back your account, still you can always try.
Fill in the form to re-apply.
https://www.google.com/adsense/support/bin/request.py?contact=invalid_clicks_appeal
As we know the chances might be low to get back your account, perhaps a few tricks here and there that I've learned from a friend can get you a new account, because Google will not allow the same banned publisher to create a new account.
- Choose a new computer to start a new blog and then apply it with Google Adsense.
- Make sure to find a new IP address so that you can login to your account.
- You must use another name (your relative?) and different address for your new account.
- Login with new computer and IPs to access your account, never use your previous PC or IPs as this might get Google to find out the new account has correlation with the previous one.
Note: This does not apply if your site/blog is banned from Google.
Do you believe or tried this before?
*One of my friend did it ^_^*
Or for prevention, you can visit Google for more information on "What can I do to ensure that my account won't be disabled?"