Unhappy with xfinity services

My mother has been with Comcast/xfinity for 14+ years at least, as she's eligible for "Diamond Xfinity Rewards". As she has gotten on in age and now suffers from Alzheimer's disease her funds have shrunk to the point she's now on government assistance/SNAP. As such I (her son) have been desperately trying to lower her bills so she doesn't lose her home. But xfinity pretty much has her locked into 500 Mbps Blast plan of which she only gets around 180-90 Mbps BTW (atrocious), for $112 a month. She can not afford this anymore. I've been trying for months, with "live agents/ambassadors/whatever they choose to call themselves" to get her bill down, but the only "offers" available "in her area" is the current plan, or a limited 150 Mpbs at $80+ a month. How ridiculous is that? Very. It's as if the tactic is to have her locked into the current plan (that keeps going up) that rips her off hard, or she can get ripped off harder. No other plans available apparently. Unreal.

I tried to sign her up for "NOW Internet - Affordable Internet", the 200 Mbps plan for $45 a month, since she gets a bit less than that speed anyway. $45 or less would be ideal, because the difference would go a long way to help pay for her quarterly maintenance bill, but as an existing customer with a Diamond graphic in her account, she's not eligible, because reasons.

Eventually I noticed that there's a program called "Internet Essentials - Affordable Internet from Xfinity" that she should be able qualify for, given her situation and that fact that she already gets government assistance/SNAP. Or you would think, right? NOPE. Because she's an existing special customer with a Diamond graphic she can not apply for it. Another arbitrary limitation imposed on supposedly cherished long time customers. As if situations and life changes don't happen to special Diamond people.

So, as you can see no matter my approach, it is seemingly impossible to get her a reasonable internet plan that she afford. Comcast essentially has a monopoly here, to top it off.

Who would be happy with that? I'm certainly not. She wouldn't be either if she could understand what's going on. Unfortunately my poor mother can't anymore, and I'm just trying to save her home and make her comfortable. This is all so messed up.