Modem/speed issue and tier pricing lock out

Hello!  In January 2026 I called Xfinity to see if something could be done to lower my internet bill (I saw there were promos for new customers and every year or two I make the call).   I was interested in either staying at 300 (which I was paying $79, but the new customer price is $40) or 500 (which the new customer price is $50.  The rep I spoke with said the tier I could have was 1 gig at $60.  I said it was more speed than I needed, but he was adamant  about the 1 gig and how wonderful it would be.  But what he failed to acknowledge (which your AI determined when I logged in to chat regarding my modem speed, is that my modem wasn't compatible with 1 gig speed -- and my internet has been buffering and now averages 4.1 Mbps.

  I called to return to the correct speed for my modem and was told that it was no longer available TO ME at the reduced price.  It is available to new customers, just not to me (so much for your appreciating my 28 years of being a loyal customer).  Apparently I got my deal in January and even though Xfinity made a mistake you won't provide a reasonable remedy.  I was told tonight by a "customer loyalty/retention" person that "maybe next month it will be available" BUT she will send me an Xfinity modem (which is now free! lucky me!) to "fix" the problem.  I declined (the modem is really being pushed, which really makes me not want it).  I was also told today that "no one in Xfinity can help me", and the rep said she was telling me that to save me from wasting time by calling again.  I told her I didn't believe it was true that "no one can help me" but I did believe it to be true that no one at her level (a supervisor with "customer service") was given the authority to fix this.  Another rep told me today that I am locked out of any "deals" and if I want to stay with Xfinity at the tier and price I have I will either have to use the Xfinity modem or buy a new one (even though the one I have isn't that old and will work fine with the lower tiers).  So here's my question:  Is what I've been told true.  No one in Xfinity is able to correct the Xfinity caused error and put me at the lower tier I originally wanted at the price I originally requested?  Am I "locked out"?   

So it's clear here's what I am requesting:  Either 300 Mbps at $40 or 500 Mbps at $50, which was the offer in January and is what I called and originally requested.  The offer is still available today to new customers.  This will fix the problem your employee created with the least disruption to me, your loyal customer for 28 years.