3-Year price guarantee reduces to 24 months

On 2/9, I ordered 1 Gigabit Internet Plan for $60/mo ($10 off with autopay) with price guarantee for 36 months. However, after completing the order, I keep getting confirmation emails saying 24 months. I spoke to 2 different chat agents and they assured me that I should receive new confirmation for the 36-month guarantee. Yet I never did. The 3rd chat agent referred me to talk to his/her senior. I responded that I did not want more talks and that I needed a simple and quick answer in writing. The February statement says: "[Regular price $115] Includes a 24 month $35.00 Promotional Discount. A portion of this discount will end on Feb 12, 2026. The remainder of your discount will expire when your promotion end on Feb 12, 2027. " The vague language, such as "A portion of this discount," and "The remainder of your discount" should make one nervous. What is clear to me is: After 2 years, I will pay more, which is contrary to xfinity's 36-month price guarantee. One more thing: After I created my account online, the 3 year price guarantee ad no longer shows on my browser. As an IT professional, I easily understand that it's the work of the xfinity cookies. I switched to a different browser without login, the 3 year price guarantee ad appears intact. I can't help but think:
Is this an honorable way of doing business? 
I'm sure this does not happen to me only. [Edited: "Solicitation"]