Chat Customer Service Said They Adjusted My Payment Arrangement and Cancelled the Payment But Payment Processed Anyway. NO HELP!

I was basically forced to use the chat online to connect with a customer service agent - "Klaus". He said he was going to help me adjust my payment arrangement from the 18th to the 31st. He said he was going to cancel the payment I had setup on the 18th and I can login and make my payment on the 31st. I woke up this morning (the 18th) to an email from Xfinity saying "thank you for your payment". Now my bank account is going to overdraw. 

I call customer service and they say they do not have access to the chat transcripts and Klaus did not make any note or any adjustment to my account. The agent tried to see if his supervisor could cancel the pending payment and the supervisor said they won't do it because it was a promise to pay and they can't verify the convo I had with Klaus. HOWEVER, I HAVE THE ENTIRE CHAT I CAN EMAIL TO SOMEONE!! But they won't let me send it and refuse to help. I go back to the chat and am told something completely different. This has been the most frustrating experience I've had with Xfinity yet and I am going to be calling to cancel if no one can help me with this. I did everything I was supposed to do to move the arrangement and payment but the chat agent did nothing he said he was going to do. Now, my account is going to overdraw or I will be returning the payment and my services will be shut off. I need them to work so this is beyond frustrating! 

It's insane to me that the phone customer service agents don't have access to the chat info and that leads to issues like this!