URGENT: 44-Year Customer - Seeking Executive/Billing Specialist for Legacy to Next-Gen account error (Due April 8).

My family have been customers of Comcast for 44 years and I am extremely distressed by a billing error that began on March 19.
On March 19 i entered a Tech support chat about a streaming issue on my TV. The tech agent was unable to fix the issue,
as an apology she told me about the Disney+/Hulu/ 1Gig 36 month bundle. I mentioned that was an interesting offer, but i did not want my plan to change as i was happy with our
Legacy Plan, but the offer was interesting to me. At no point did this tech agent say that i had to switch plans, in fact she made it sound like she could add it to the legacy plan.

Around the dates of March 20th to March 22nd On the account log in under the billing make payment section, to my shock i discovered our April 8th bill now said the due amount is $728.27 and the billing agent said we had been double-billed that amount and the listed amount was in error. 

I have contacted billing support everyday March 20th to March 30th over this double billing, each time the billing chat agent, agrees that  the error was made on March 19th by that technical agent not having access to my billing and had moved my plan from Legacy  to Next Gen plan without my knowing.  Each time the agents explain that to accept that offer, we had to move plans, they have fully explained the plan to me and in their time with me each time I have been professionally assured that the "wrong statement" would be removed and replaced with the correct one within 24 hours. However, this has not happened.

Each billing agent  that has worked with me on this issue ,has told me that this is an Xfinity error and that we do not owe $728.27 ,they offer  an apology ,credits and assure that they will correct the problem and I will never have this issue again , yet nothing is corrected. Each billing agent  has stated  my ledger actually  has a different amount  to pay ranging from $58 to $407 for April with the agent on Sunday saying the bill is $362.39 .At the end of each billing chat they apologize that this happened and assured me this is corrected.

The statement on our account up to this minute says we owe $728.27 on April 8th, billing agents clearly say this is an error of Xfinity`s making. My bill is due April 8, and I cannot risk paying an incorrect amount or having a massive overcharge pulled from my account.

I am requesting an Official Employee to manually review my ledger, correct the statement that is listed in the payment area of my account, and provide me with a single, accurate balance before my due date. Please invite me to a Direct Message so I can provide my account details privately.