Maintenance in local area & reduced speeds

Posting this here as I've exhausted all other options and can't get anyone at Xfinity to answer my questions or confirm what is going on with my network.

On 5/25, I was informed Xfinity would be performing a "network upgrade" in my area. I was properly notified weeks in advance, all was well and good, no problem. Appreciated the transparency and the heads up notice. Prior to this .. "upgrade" .. I was paying for a 1 gig plan with about 40mbps download speed and hitting those speeds on a consistent basis, with no connectivity issues or slowness. As of 5/26, my speeds took a SIGNIFICANT turn for the worse, and I do not come close to consistently getting the speeds I'm paying for anymore. I even upgraded to a 2 GIG plan to try and circumvent the issues I was having, still .. no luck. (I am talking Ethernet speeds as well, not even talking about WiFi or devices hooked up to WiFi)

I speed test every day, throughout the day, and only once (right after upgrading my plan) did I hit 2 gigs. During the day I mostly hit 1000-1400mbps download speed. And EVERY NIGHT since 5/26 from around 8:30PM EST to 11:30PM EST, my speeds drop to 400-500mbps download speed. There has been no difference in internet usage, no new equipment installed or moved, nothing different. Seems after Xfinity was in my area doing a network "upgrade" speeds have reduced dramatically, especially at night. For $200+ a month? To not come anywhere CLOSE to the speeds I'm paying for, is outrageous. I'm not even getting HALF the speed I pay for and no one can offer up any solutions or answers.

I've TRIED talking to customer support on the phone. He couldn't understand what was going on and tried to just brush me off by giving me a "credit" on my account. Which, I still have not seen a single cent hit my account from Xfinity. The rep was rude and tried getting me off the phone instead of trying to understand and help. I asked to speak to a manager or have one call me back, I was assured someone would. No one did (shocker). I have chatted with the Support team via  Twitter, still no resolutions that have been helpful. I've connected, restarted, unplugged my modem hundreds of times. I've checked all cables and coax connections. I'm plugged in via Ethernet. Nothing is working to fix my speed issues, particularly at night. (I thought Xfinity "doesn't and won't ever throttle" internet speeds??) 

I was told NUMEROUS times that "no other work was planned in my area". Which is not true. Because the Xfinity site has now, twice, since 5/26 informed me to "Prepare for Outages" and that additional network performance work was being done in the area. So, what's the actual truth here? Is work being done to fix this? Or not? How long is the work expected to be going on for? A LITTLE communication goes a long way, Xfinity. Stop leaving your customers guessing, and stop offering up bogus answers and troubleshooting responses that are less than helpful. 

I have a sneaking suspicion that this was a result of the local "network upgrade" and Xfinity is now trying to hide that something seriously got botched.