Unfair Billing Practice Via Xfinity Agent on Phone - Unexpected Fee Increase

I will make this simple, even thou it took one hour and 45 minutes of my day away on phone calls. I called Xfinity and was connected with a rep. I explained my "IN Contract" bill had increased a lot for me. I knew there was some excuse as to why this could happen, because no one can read the 100 page contract. So I kindly asked if she could fix or change my service to more reflect my previous bill. She checked and checked. And came back with a great compromise. She said 1GB internet (Win), unlimited data, free equipment, and she even threw in peacock premium for 2 years free (Win), I just had to loose 75 channels, and move to 125+ channels (Loose). Ok. I was kinda alright with that because I am not into the cable tv experience anymore. It was still going to be $2.50 more than my December bill, but less than this January bill. This is after 47 minutes and 27 seconds as my phone says. She just had to transfer me to or put me on hold, but I ended up getting transferred to xfinity phone support? This guy was nice and said he would get me back, but hung up. I called back and reached another consumer rep and explained entire situation again. "Ace" informed me after we had talked for another 49 mins and 7 seconds, that that offer had changed, because their promos change often. I said it had only been 49 minutes and it was a mistake by your company why I was disconnected. He just again said he could not honor that price, becaue their "promos change often". Well if they change every 40 minutes thats a miricle or a lie? And pretty deceptive. He then quoted me over $200++, I am not going to even put in the price. But I have both quotes on phone. Same exact service, same exact options, massive difference for ME!  And I have been a long term customer. He would not budge or adknowledge it was only 40 minutes since lower quote (EXACT SAME SERVICES). It seems so deceptive and borderline illegal? I have a hard time understanding how they get away with it? Other than the Billions they make. I never complain about their outages or poor connections, or service update/upgrades that take place during my primetime usage time of 1am to 6am. Can someone please explain to me why one agent can give one quote that is so far apart from another. And why this is allowed?