If your wordpress installation is getting hacked, it is due to one of several reasons:
- Your installation is not at the latest version. Upgrade.
- One of your themes has a vulnerability. Upgrade it or delete it from your installation. Note, a theme doesn't need to be active for it's php code to be triggered remotely.
- One of your plugins has a vulnerability. Upgrade it or delete it from your installation. Note, a plugin that is disabled can still be hacked.
- Your version of PHP, Apache, or Mysql may have an issue.
- The hosting environment might have a security issue.
From your post, it's hard to tell where it could be coming from. If you are hosted via GoDaddy and upgrading the Wordpress site isn't an option and you don't want to host it on your own server, then I suggest hosting through Wordpress themselves and pay so you can have your own custom domain.
If you are not hosting on GoDaddy and you can upgrade the base install, then do so. But since you've been hacked once, I would:
- Do a full dump of your database, checking it for any potential problem records.
- Starting with a clean VPS/server, install a new copy of Wordpress and slowly re-add your content and plugins.
- Backup regularly and monitor for file changes.
Basically, once your site has been hacked, I would suspect any files on the box.