It shows on my Blue Cash credit card. Not sure whether AT&T/Comcast internet counts or not.
Here is the description:
Get 10% of your online payment back as statement credit each time you use your enrolled Card to pay your US Cable or Satellite television bill online directly with the provider by 9/30/2018. Limit $20 in total credits. See terms for exclusions.
Here is the terms:
Enrollment limited. Must first add offer to Card and then use same Card to redeem. Only U.S.-issued American Express® Cards are eligible. Offer valid on US bill payments for cable and satellite television services made directly with the provider. Payments must be made directly with the provider online, via mobile app or by phone. Payments made at service centers do not qualify. Payments for hardware, installation, and other services are excluded, if not bundled and charged with monthly service bill. Excludes payments for satellite radio services and subscriptions with streaming television providers. Offer is non-transferable Limit $20 in total statement credits per American Express® online account. Statement credit will appear on your billing statement within 90 days after 9/30/2018, provided that American Express receives information from the merchant about your qualifying purchase. Note that American Express may not receive information about your qualifying purchase from merchant until all items from your qualifying purchase have been provided/shipped by merchant. Statement credit may be reversed if qualifying purchase is returned/cancelled. If American Express does not receive information that identifies your transaction as qualifying for the offer, you will not receive the statement credit. For example, your transaction will not qualify if it is not made directly with the merchant. In addition, in most cases, you may not receive the statement credit if your transaction is made with an electronic wallet or through a third party or if the merchant uses a mobile or wireless card reader to process it. By adding an offer to a Card, you agree that American Express may send you communications about the offer. POID: GB7D:0001