Are there any customer service representatives who will actually listen to me and help find a solution?

I have been indirectly called a liar by 3 different reps after I've explained my elderly mother's past-due billing issues.  I am trying to resolve, as in PAY, a past-due balance on my mother's account, but I need a payment schedule I can afford.  Last year and into this year 2024, she was on some kind of hardship plan, paying $30 a month for a few tv chanels and so-so internet speed PLUS she was receiving a credit from another low income program for $30 a month.  So she paid nothing for many months.  She was informed that the low income credit program was ending, so she budgeted $30 a month for her new bill.  Simple enough math.  About six weeks later she showed me a notification she received from Xfinity about a past due balance of over $200.  It turns out that WITHOUT any consent from her, her account had returned her plan to the level of lightning internet speed and the major tv channel line-up that she had almost a year prior when I lived with her and was paying for it.   We called immediately and requested her plan be reduced to bare minimum and I agreed to a flex plan to pay off the past due (of which I have made 4 payments and cannot see where they have been applied).  Another billing cycle later and the overdue balance had more than doubled and she was being threatened with service disconnect!  We rushed to an Xfinity service center where I could look into the white's of a human being's eyes and insisted on reducing her plan to the cheapest possible.  They did oblige but could do nothing to help with the past-due fiasco.  I was to call the 888 number where they can resolve such things.  However, every time I called I was told there is no way this mess could happen -that my mother would have had to sign a new agreement and yet, no signed agreement can be produced.  In order to prolong her service and buy some time to resolve this issue, I had to make a payment arrangement. But my timeline and my paycheck amounts don't align with the computer-generated amount and deadline on her account.    In spite of the fact that this is not her fault, but xfinity's, I am willing to pay off her past due. Yet her service will be disconnected because I cannot pay the huge amount owed in the "arrangement".  I cannot find anyone in the ranks of customer service to take what I say happened on her account, seriously.  Because it's unusual they just say, "no, that's not what happened".  Well it DID and I need to speak with a person who gives a flip about helping me resolve this. She has been a customer for many many years.  Why is this so hard when I am trying to pay the bill?