I have the above phone that after typing 3/4 words in a text decides to re start itself! I sent one back and got a new one and now a couple of months in my new one is now doing it so I cant text

does anyone else have this problem? to have it with two handsets would suggest its a prob with the model maybe?

Any help would be appricated before I call O2 as I think I will just ask for a different phone.