For all we know, the web forms for the "customer journey" (hmmm, hate this 'creativespeak' rubbish) were changed and whoever had given the user assurance that things would go smoothly knew nothing about this change. Therefore I think it a bit strong in this case to suggest that the user was misled deliberately.
Not all that long ago, people were seeing options to sign up with no 'broadband only' and that was some <expletive>er's marketing trial in action. Some saw 'broadband and phone' plus broadband only
options, while others only saw the 'broadband and phone' options.
Confusion about whether this depended on particular browsers, etc, ensued, until a factual answer was forthcoming. I think the problem is that of marketing people thinking they know better than customers (sorry, "prospects") as to what they want, or what's "good for them" and if it means selling 2 products to 80% and <strong expletive> the other 20% who look to other ISPs, then "so be it", as they don't seem to care they are alienating possible (and as an addition, some existing) customers because of their heavy-handed methods.
If you run a business, have a second ISP and backup web hosting...