Signed up for Xfinity internet 500mbps with the promised free Xfinity mobile line - not getting it

I signed up for Xfinity internet 500mpbs line a month ago along with the stated promised promotion of the free Xfinity mobile line.  This deal was also then shown on my account.  This deal was also e-mailed to me multiple times after signing up for the internet, explicitly reminding me to sign up for the free line before the deal expires at the end of year.  Also I had Xfinity mobile for 1 year or so, two years ago ending in 2023.  

I just signed for the Xfinity mobile line and even chatted with the agent who prepared the transaction and assured me that the line would be free.  Well now, a week later or so, I'm being presented with the bill and the representative stated that this would be a second line???!!!! and thus I'm not eligible for free Xfinity mobile line.  What is this?!!