Net10 provides service for my iPhone locked to ATT. I havent had any issues with my cellular data until I updated to iOS 6. Restored, issue persists. Contacted NET10, and found this information:
-called 1-877-836-2368, provided my cell number, got a rep after about 10 min.
- rep says that cellular data has been suspended on the iPhone due to "high data usage".
-transferred to "High data use" line, which gave me these instructions on how to resolve this:
-You are hearing this message because your data service has been suspended in accordance with our terms and conditions
-AT&T compatiable sim cards are being capped at 1.5 GB of data per month, effective march 1st 2013
-this does not apply to Tmobile compatiable sim cards or to Net10 phones.
-Visit Net10 net10data.com for terms and conditions
-AT&T sim card, resolve by unlocking iPhone
-data service will be restored 24 hrs after adding a new service card or a plan AFTER your service enddate. Adding a service card BEFORE your service enddate WILL NOT restore your service.
-so get the phone unlocked, and then make sure to add a plan or pin AFTER your service expires.
-call the number above for NET10 customers to make sure this is the issue as well
i hope this helps!