I factory reset my Galaxy Mega 5.8 (gt-I9152) And now my apn is blank

[Johnny239]

I got this phone as a gift through QVC as an unlocked GSM phone. I took it to AIO wireless and they turned on service and did the initial connections. phone has exceeded my expectations for almost a year now. I had a Issue with WIFI and factory reset has worked to repair that issue I have all the APN info that I need to manually input into the phone but when I open that sub menu it is a blank screen and I dont know how to get it unlocked or accessed. If someone has an Idea that would be helpful thanks