Cannot change APN
I bought an iphone 5s from AT&T a few years ago. Last year when I moved abroad, I paid to have it unlocked from AT&T. This summer I am in the US and want to use my phone for the month through Net10. I am able to use it to call & to text, but I cannot use my data plan that I have paid for. I have been told I need to change my APN, but I am not able to manually do this. Net10 & Apple have told me I need to have this done through AT&T. How can I do this? Thank you!