Charges on recent statements not consistent with upgrade to the new 1 Gig service plan I purchased last October

After noticing charges on a few recent monthly invoices that are notably inconsistent with the products and services in the new 1 Gig plan I bought in early October 2025, I'm finding a multitude of problematic billing items going back to every statement following the purchase of my upgrade from 800 Mbps. For starters, it appears I did not actually get the increased download speeds and unlimited data usage that I signed up for in October. I have received charges for exceeding a 1.2TB data usage limit (my new plan should include unlimited usage). Other examples are not receiving the monthly discounts that are in my new plan as well as getting $15 equipment rentals charges on a few statements where the new Gateway equipment I received in October should be included at no extra cost.

The frustrating part is I spoke to a customer service representative via telephone on January 4, at which time I thought we had things worked out (I did receive some credit on my account). Unfortunately, I’m still seeing billing errors on statements for January and February of this year. Note that all these invoices have already been paid via Auto-Pay except for the February 2026 bill for which payment is scheduled to be automatically collected tomorrow (2/19/26).

I’ve downloaded copies of statements as well as all email correspondence from Xfinity confirming the changes to my plan. I also created a spreadsheet showing the chronology of transactions and communications with detailed notes on every problem I found in my last five statements. I’m wondering about the best way to present these documents to customer service or whomever best suited for offering assistance. Thank you,