unable to delete some txt messages

Got the other half a samsung galaxy s3 mini for crimbo , yesterday she spotted 3 txt messages with the numbers 32665011 , 32665010 and 32665005 , the prefix seems to be something to do with facebook ( i maybe wrong here )
every time she tries to delete them they just dont go from the inbox , they are empty threads.

Not being clued up on android ive not got a clue where to start , have tried a few apps that claim to delete txts but no joy so far , any ideas guys ?

Switch the phone off and take out the battery then try again, If it dont work try
also *download history eraser which is free and try and delete them threw that just tick delete messages/clear app caches/clip board etc etc
you can pick which messages to delete IE sent/received/draft/failed