Eligibility for Device Payment Plan

I have been an Xfinity Mobile and Internet customer since last year. I have had no issues with late payments and I have excellent credit. When attempting to upgrade and trade-in my phone, my credit was frozen and I was deemed ineligible for a payment plan. I have since lifted the freeze and should be eligible. I have tried calling and asking for the previous credit check to be cleared and a new one run, but no one has been able to help. They just tell me to keep trying. This is very frustrating. I've been trying to buy a new phone for several weeks now. Can you please help clear my previous credit check?