Adding Unlimited Data Plan with Own Equipment

Hi,

Anyone else get stuck in the error loop when attempting to add unlimited data to their plans using their own equipment?

I go here, where they lead when you click the help link for data "overages" 🙄 on your account page (seriously, data overages. Like it's 1996, and data is somehow a scarce or quantifiable metric to use for billing purposes or anything reflective of who uses the internet bandwidth "more"): https://www.xfinity.com/learn/internet-service/data?CMP=ILC:PD:BAU:ALL:COM:GEN:INT:NA5f495019eb20f

and click the link about halfway down and click "Get Unlimited" because if I see another extraneous 100 dollar overage I'm gonna lose it: https://www.xfinity.com/buy/plan/checkout/XFINUDAT

It goes through the motions before dumping me to a "Sorry, that's unavailable right now, try again later"  page, saying:

https://www.xfinity.com/error/buy/sorry?errorCode=DFPLN4000

Temporarily unavailable

The product you’re interested in isn’t available for purchase at this time.

Get updates about Xfinity Home, Xfinity Cameras, and 24/7 Video Recording.

I've tried adding it every 3 days for the last 4 months, to no avail. The customer service robot just directs me to purchase an xFinity Gateway, which I'm not going to do. The data caps in general are already unbelievable and embarassing, but the expectation to keep any household under 1.2TB when everyone is streaming multiuser video calls 9 hours a day and then streaming HD/4k footage when they're not doing that is not only impossible, but quite frankly a bit insulting. Charging an additional arbitrary amount to cover their hemmoraging TV and phone service to the only product they produce that's actually worth anything in internet service is, while hilarious, something I'd be more than willing to pay to never see another random 200 dollar bill because of their topsy-turvy moon-person attempts to sell people on the "quantity" of data somehow having more or less value, despite the only thing of value being sold to the customer being bandwidth. 

I want to give the clowns at Comcast corporate the extra 30 dollars of blood money a month to get unlimited data with my own equipment, and honestly it's making me consider CenturyLink's gigabit plan in my area. At least they don't have data caps.

None of this ire is directed at whatever poor community manager or customer rep gets stuck reading this stuff, I imagine it feels pretty terrible to have to work for one of the worst companies of all time, and the reason they're terrible is entirely based on decisions of people that are essentially untouchably wealthy, which is gross as all get-out.

I literally just want to be able to pay for the service being sold, and this janky website apparently is intent on having that not happen. Is this some elaborate scheme to get me to call a hotline? There isn't even a human-staffed chat tool.