Overage Charge not being removed

My Xfinity app told me last month that I would not be charged for going over on data usage and I confirmed this with Xfinity chat agents last month. See screenshot below indicating "we'll waive the additional charges as a one-time courtesy". I was charged $100 for overage and I've now wasted SO much time trying to get the additional charges removed. Multiple live chat agents have told me that this is just the overage policy (which I understand as I've had previous months where I've gone over), but they continue to ignore my comments about the fact the Xfinity app told me I wouldn't be charged as a one-time courtesy. Instead, they tell me I should be updating to unlimited data which costs more, instead of trying to help me out with correcting the charges. I got one agent to remove $60 of the charge and told me the other $40 would be removed within 24 hours. As expected, the additional $40 was not removed and here I am wasting more time trying to get this corrected. How can I get this corrected and get compensation for my time wasted for something I was told I would not be charged for per the Xfinity app?