Enter/Return key for text messages?

I tend to send longer texts, so having a return key (to go to the next line) to separate parts of my texts is really nice. However, I can't seem to find one on this phone...why? It appears with any other text input (in notepad, for example) but when I'm writing a text message, where it ought to be is replaced by the smilies menu. I even called Google Play Device Support and they didn't know how to fix my problem...has anyone been able to enable a return or enter key for texts?

Tap the shift key and you will see the enter/return key appears at bottom right.