If you are still experiencing data connection issues then try the below link (life mobile was taken over by plusnet recently) just remember to turn wifi off to test data as it will not show up if you are connected to a wifi network. I have used this fix on 3 phones now to get data on life and then plusnet.
If you're experiencing problems using mobile Internet data on your plusnet SIM, you may want to get in touch with us. Although we're limited in how much we can help when it comes to supporting particular handsets, we will be happy to walk through common data troubleshooting issues and to check for problems on the network or SIM card.
Our Live Chat (through the mobile section of our website) and telephones (0800 0791133) are open 7:30am-10pm, and you can also email into us at email@example.com.
Hope that helps with any data-related issues going forward!