Charged for 6 Months of Service After Cancellation & Router Return

Hello — I would be very grateful for any assistance with correcting a grossly-inflated bill from an old, inactive account, which is preventing me from accessing my new account info online. As I cancelled my service on July 3, 2022 and personally returned the router directly to the store two days later on July 5, at most, the only remaining charges should properly and fairly be:

(1) the standard monthly charge for a full month of service from May 22 – June 21, 2022, and;

(2) a prorated charge for 12 days, June 22 – July 3, 2022.

The new account I opened two days ago is up and running smoothly, but when I sign in online with my e-mail address, the only information available to me is for the old, inactive account.

If you require any additional information, including a screenshot of my cancellation and a copy of my router return receipt, please let me know. I chatted online with four different agents earlier today, and would be grateful for any assistance.