K700i automatically storing messages?

Posted by generationgav
I just upgraded from a T610 to a K700i (on T-Mobile)
I got a phone call today from somebody I hadn't sent a single text message or phone call too (but I had added to my address book) to ask me why I'd sent them 45 text messages.
These messages are in my Sent Items folder and are all completely blank, even though I didn't send them.
Does anyone have any idea how this could have happened and how I can prevent it? Do I have a faulty phone and does anybody think I could claim my money back of T-Mobile for it?