When I'm signed in to the Cox.com site, why does it offer packages that aren't compatible with my TV plan?

So, if I'm a Flex Watch user, newly returned to Cox after pulling the plug a couple of years ago, when I sign into my Cox.com account and try to add something to my package, how come packages that ARE NOT compatible with Flex Watch show up? it's very frustrating to pick a package, go through the checkout process, and get two emails: one that congratulates me on my order and that the new service will start soon, and another that says that the order cannot be processed. A call in clarifies that the package isn't compatible with my base service and I'd have to upgrade. Really - the system should be smart enough to know that there is a mismatch and not even let me check out. This is the second time I've run into this, and it's reinforcing why we pulled the plug on cable in the first place. I hate paying so much $$$ for a bunch of channels that we never watch. If it weren't for Starz (Outlander!!!) and HBO, I would pull the plug again. 

Please give a la carte choices to a wider range of user. Please?