internet speed

I have the 2100 mbps download speed plan (the fastest plan offered). I receive emails from xfinity regularly stating that they measured my speed at, or above, plan speed. I just received one today that said they tested our connection at 2390 mbps. Our internet connection is PAINFULLY SLOW, all the time. I work from home and zoom/google meet freeze up and tell me my connection is unstable frequently. We switch to cellular on our phones because the wifi is always slow (we have a beefy mesh system throughout our house). I test our speed about once per week and did again today right after I received this email - middle of the day on a Wednesday. I used 4 different well-known sites, and they showed: 391, 441, 510, and 399 mbps download. That's an average of 435 mbps... almost 2,000 mbps LESS that xfinity says they show. On my weekly tests (I take dated screenshots), my speeds range from 2 mbps (seriously) up to just under 600 mbps. Our equipment is pretty new and the most expense they offer. I'm the only one online. I have had techs come out and replace cables and connections, check the main box outside, etc. They have sent new signals, etc. We've lived here 2 years and it's been awful (FiOS isn't here yet, so I have no other options except satellite). I get texts from the xfinity assistant frequently stating they are aware our service is experiencing problems or outages. Multiple times per week, sometimes. I have spent hours on the phone with customer service but the best they have done is $30 to $60 credit off our bill.

Has anyone ever been successful getting xfinity to take a solution seriously? [Edited: "Solicitation"]