no warning for charge for additional data

Concern moved here to the Billing help section for greater exposure to Comcast corporate employees (The Digital Care Team) for assistance. 

Hey there user_2m3jbd 👋 You're in the right place for help with your plan, and I appreciate you stopping by! With how frequently things are coming and going online nowadays, data caps can cause a lot of issue if you're like me and download huge stuff regularly, so I definitely understand the concern about overage charges. Xfinity is more than understanding of this, which is why your gateway rental along with unlimited internet data come with all of our new plans completely free of charge as a standard feature regardless of the plan you pick 🙌

With our legacy internet plans, that data limit was capped to 1.2TB worth of data unless an unlimited add-on was present, causing charges in $10 increments for every 50GB of extra data used up to $100. For more information on these data limits, please check out https://www.xfinity.com/support/articles/data-usage-plan. 

All that said, we'd love to get you setup on an updated plan to ensure you're not only getting unlimited data for your internet, but also the best rates possible! To get started, please send us a direct chat message with your full name, the name listed on the account (if different), and the full service address associated with your account to “Xfinity Support”.

How to Send Us a Direct Message:

1. Click "Sign In" if necessary.
2. Click the "Direct Messaging" icon or visit Xfinity Direct Messaging.
3. Click the "New message" (pencil and paper) icon.
4. In the "To:" line, type "Xfinity Support".
5. As you type, a drop-down list will appear. Select "Xfinity Support" from that list.
6. An "Xfinity Support" graphic will replace the "To:" line.
7. Type your message in the text area near the bottom of the window.
8. Press Enter to send it.

You can see how to send us a direct message here,

How to: Direct messaging within the forum | Xfinity Community Forum