Xfinity upgrading issues!! I'm fed up!!!!!!

So, I got 2 iPhone 13s and a z flip 3 5g a year ago(almost $3,000 worth of phones) I have made 13 of the 24 payments which once 50% or more is paid off of each device, I am eligible for an upgrade. So, I did that. Paid over the 50% that was required. So, online,it states for each line, out beside each phone, it states "this line is eligible for an early phone upgrade" and tells me to go to the store and return the current phones. It stipulates that as long as the phones are in working order, and my account is in good standing I may get a new upgraded phone. I combed through the policy online as well. I meet all qualifications. BUT, when I went to the store the get the new phones XFINITY SAYS I AM ELIGIBLE FOR, they say I can't get new phones because of my credit?? What????!!!!!! My credit score is 150 points higher than it was a year ago when I got these phones in the first place. Furthermore, the guy in the store says that it is showing I am only eligible for -$1036. Yes, NEGATIVE $1036!!!!!   How is that even possible to be eligible for a negative balance. Something is severely wrong here and now my 2 daughters Christmas gifts are ruined bc they thought they were getting new phones today for Christmas. Xfinity needs to figure out what in the hell is wrong with this situation and fix it fast or I'm done with Xfinity for good. This makes absolutely NO SENSE WHATSOEVER!!!!;