Sorry to read of your troubles. Though it has been quite a while ago, periodically we have noticed similar issues over the course of the past couple of years. Typically the problem vanishes as mysteriously as it appeared. As a precaution, we like to ensure we are on an actual GoDaddy page and not an affiliate or sub page from another small seller, as sometimes happens.
Take a look at the toolbar to ensure there is not a pre-existing code or additional jargon after godaddy dot com. Sometimes these affiliate pages or sub-seller pages auto-add services to get commissions, funds, etc; from unsuspecting buyers.
At any rate, though there are glitches that can happen, we tried several times but did not see the add-on mentioned in your post. However, we will continue to monitor the situation and update everyone should we experience any suspicious activity or similar findings. We hope you all will do so as well. You may want to alert GoDaddy Support about this issue, especially if it continues to happen. Their number is 480-505-8877 (also found on their homepage in the uppermost right corner of the page.
---> This is a good reminder for us all to inspect our GoDaddy accounts on a regular basis, ensuring all information is correct, any credit cards being saved or stored on file are there because you choose, all paypal accounts match and are up-to-date, and all names you want to renew manually vs. automatically, are set properly according to your choice and are tied to the proper credit card or Paypal account.
Thank you in advance for bringing this issue to light for us all. As another precaution, we recommend clearing all cookies, closing out of windows, fully rebooting and then running your virus checker to ensure your system is clean, clear and free of any malware or spyware.
Sorry for the lenghy post. Happy Domaining to all.
-Regards