Not eligible for a credit?

I called to upgrade a phone on my account and was told I was ineligible for a $200 credit on the upgraded device because my credit score wasn't good enough. My credit score was good enough to purchase the phone at full price though. I am very disappointed with Xfinity. I have been a customer for over 10 years. All of my devices through Xfinity have been paid in full. I owed nothing except my monthly bill. I went ahead and purchased the same phone I was looking at through Motorola directly.I will say that the customer service representatives were very helpful and tried to get the credit for me but were unable to.