Payment plans

I was trying to upgrade my device. A few weeks ago when I was going to do it I had the option to pay the device of in installments. Now my only option is to pay the device off in full. I only have 1 item on my account left with a $7.25 balance to be paid off in full. There are no other installment plans on my account. Do you know why I wouldn't have the option to make payments to pay the device off?