Maybe try the forum search function..
Click on the blue Star Icon below if my advice has helped you or press the 'Accept As Solution' link if I solved your problem..
I have reset my phone, asked for help of Vodaphone and looked at the search on Nokia with no results. I have created a group under People, however there are no options to send an email or text under the group name. I have also tried to send a text to a group but the group option is not displayed only the contact list. this is so frustrating.
Have you checked this thread: http://discussions.nokia.com/t5/Nokia-Lumia/Group-
The thread is Lumia 710 but still the same.