Really sorry to hear about your recent experience. It does sound like there was mis-communication in regards to the features and functions of the Online Store service we offer and what you were specifically looking for.
As you've pointed out, the Online Store only secures the shopping cart sections of the site where account information and billing details are gathered and processed from the shoppers. As these sections of the site are already secured, our separate SSL services can't be used with Online Store as these certificates are meant for installation into stand-alone hosting environments without any prior SSL installation files present.
We appreciate you taking a moment to share this much needed feedback which i will pass on to our teams who will need to review this for improving our communication and product features. Again, my apologies for the experience.
CG - GoDaddy | Community Moderator 24/7 support available at x.co/247support