Escalation

On 3/21/24, I switched to xfinity from Verizon.  This was the last day of the BOGO Unlimited Intro.  This would mean a normally $60 charge/month for two lines and would be $30/month for the period of 12 months.  At the same time, my son and daughter-in-law split from my Verizon plan to get their own BOGO Unlimited Intro.  For the past 6 months, I have been overcharged $10 each month on MY account since I was somehow bumped up to 5th Generation.  My son's plan has been just fine with the appropriate $30 credit each month.  I have had to call, chat, and beg for every $10 credit every month and the case has been ESCALATED multiple times with NEVER a resolution.  I have been told it is well-documented, but I still must contact xfinity every month to have the same time-consuming nightmare ensue.  I have asked to be put back on whatever generation was before this one...or whatever needs to be done without this huge hassle. I am reassured by every agent (likely a dozen by now) that my concerns will be remedied, and although the agents seem confident...it's the WORST overall company customer service EVER!  How can I get resolution where I am getting the appropriate credit every month?