Customer service

Can someone tell me how to get help from Xfinity/Comcast? I have been trying since January 11, 2021 to get an adjustment on my bill for an installation fee. When I called in December the agent told me if I brought all three services (landline, internet and tv) to Xfinity/comcast there would be NO INSTALLATION FEE.  Until February 3rd I did not have a landline. I have lost track of how many phone calls I have made.  I always get the same answer, WE WILL TAKE THAT OFF YOUR BILL.  To date they have not.  On February 3rd....because I called them.....someone signed off the order.....so I could finally see my bill! They added a $10 late charge, and also "the system generated a cut-off notice." I said, I just got phone service.....and at that time I still did NOT HAVE BILL.  I am asking myself almost daily.....WHY DID I SWITCH TO COMCAST/XFINITY/