I have the LG Optimus F7, until last week everything was fine. Now no matter the SMS app I use (and I've tried with about 4 different ones now including the stock app on the phone) I can not send or receive a group text. I was using Chomp and had been for months and it was fine, on Saturday it tells me it can not download because of my APN settings. No matter what I did, or changed it told me the same thing. I uninstalled and tried different apps, I don't get that message anymore, just that system is unavailable and will send when it can. But it never does. How do I fix this? There are 4 of us that text as a group very often.