Billing is INCORRECT EVERY MONTH!! It's reoccurring regardless of how many times I speak w/ them

I have had no success contacting the customer service after multiple attempts with bots or people that just don't understand anything while reading a script.  I've spent hours on the phone trying to correct these issues.  I am being charged an extra $25 a month for my internet service for XFi complete even though I am supposed to have a credit for $25 a month for an entire year, which started in November.   It got removed from my account after they had to switch out my modem that didn't work.  Multiple people at Xfinity have told me they "can't do anything" or "they have fixed it" or "someone will call you about it!" and then nothing happens!  I mean come on! It's absolutely ridiculous!    I also have my bill auto drafted every month, but NOW I have a $10 late fee for the $25 fee that was added later after my auto draft went out.  How can one have any late fees when their account is auto drafted?  I need to have this issue fixed immediately and I don't want to sit on the phone or messenger going back and forth with someone.  I need to be credited for my past payments and my credit put back on my account for every month going forward.   In all my life I have NEVER dealt with WORST customer service in my life or just the LACK OF IT!!.  My wife has already ordered another internet service to try out, but I am trying to give this one last shot because I don't have a problem with the actual internet, just the fact I am being lied to and ignored while being charged for something I should NOT be charged for.  I had AT&T for 14 years and NEVER had 1 issue with them.  Only reason we changed was so we could have faster internet, but if this is the way Xfinity treats their customers, then its not worth it.