Why am I not getting the free unlimited mobile line that was advertised to me?

Hello Xfinity mobile support,

I signed up for two lines of Xfinity Mobile last year after receiving several notices in the mail, advertising a free unlimited line to me, which I believe I am eligible for.  See below/attached for photos of one of these notices I received.

But still I am fully billed every month for both of Xfinity mobile lines, why is this? Can you help me with this?  I have tried calling and the live chat, but no one seems to be able to help.

[Image Removed: "Personal Information"]