Ridiculous Xfinity support

Recently my area has upgraded to enhanced speed.  Then the whole dysfunctional Xfinity nightmare starts.  I am on 1.2Gbps/35Mbps plan.  After upgrade, on my "Change Speed" page, it started to show I am currently on 2Gbps plan.  Wow, good news, right? No.

First, I contacted xfinity online support, just to confirm I am on faster speed. I was told by support I am indeed on 2Gbps/250Mbps speed.  Since I am using my own modem which doesn't support mid-split for higher upload speed, I requested a xfinity modem because my plan includes free modem rental for one year.  Support said I can pick up at local store.

Second, I went to local store specified by online support, one employee checked and said he couldn't find my order.  Then I explained to him my story, he then said "No, you cannot get a modem, you can ONLY get it when you initially sign up".  I tried a couple times, he just insisted and looked at me that I was wrong.  I asked for manager.  Manager came, repeated same story, tried to add modem for me, but unsuccessful.  Manager said the only way I can get modem is by a new one.  [Edited: "Language"]

Third, I went back online support and told them my unhappy story, this time online support did the right thing and re-ordered modem for me to pick up at different store (Thank God).  The process was flawless and picked up modem right away.

Forth, installed xfinity modem and activated, speed test showed I was still on old 1.2Gbps/35Mbps.  What?

Fifth, Talk to online support again and quoted original support chat history.  Now support said you are still on 1.2Gbps plan.  Back to square one.

This is an untrained and unprofessional crew that supports xfinity customer.  I wasted time dealing with them for nothing.  This is unbelievable!