08-29-2012 05:11 PM
Hi and Welcome to the Community!
Anytime random strange behavior or sluggishness creeps in, the first thing to do is a battery pop reboot. With power ON, remove the back cover and pull out the battery. Wait about a minute then replace the battery and cover. Power up and wait patiently through the long reboot -- ~5 minutes. See if things have returned to good operation. Like all computing devices, BB's suffer from memory leaks and such...with a hard reboot being the best cure.
That said, you definitely need to talk to your carrier...SMS is solely part of your voice-level services and not any part of your data level services, so nothing from the RIM systems is even involved.
Further..."they don't get sent"...can you provide a bit more detail? Exaclty what do you do? Exactly what happens? What do you see on your screen? From what you said, it's a bit hard to understand exactly your situation.