Upgrade issue

I am trying to upgrade my BYOD iPhone line, but the system blocks me with a 'DPP line limit' error. The checkout only works if I pay in full. My online dashboard only shows 1 phone, but your system is registering 2 devices on this 1 active line. I need a Tier 2 technical agent to clear the ghost IMEI/hardware association and refresh my DPP line allowance in the backend billing system.