Payment plans on new phone (Go Phone)

so I been a customer with AT&T go phone for over a year. About 2 if I'm correct and I was advised that after 6 months I could upgrade to a different phone. My question is am I able to get an iPhone 5c and instead of paying the full price can I make monthly payments? So if the phone is about 300 make 40.00 monthly payments or 50 and that be considered my phone bill as well? Is that possible with go phone?? Somebody please help me with a correct answer. And as much detail as possible.