Mobile upgrade

I have been with Xfinity Mobile since 2006.  Xfinity cable even longer.  I have 2 paid in full phone lines, one with 4 payments remaining and one watch which was purchased and added to my account.  For a total Four lines. Two lines are unlimited data and one line by the gig.  The fourth line is a watch connected to an existing phone line. I was told the following below via Chat 

Unfortunately you do not qualify You may chat back with us after 20-25 days to check for the credit limit.

I get your point and where you are coming from, I wish I could do this for you however, it depends on the credit limit on your account .

However this is on the website regarding upgrading: Upgrades available after 12 months on eligible devices or 50% of your current device has been paid.

Fees apply for upgrades.

Upgrade fee is waived if you're enrolled in the xfinity Mobile Protection Plan.

Nothing about credit limit on account.  Keep in mind payment are automatically withdrawn every month