I have just received my new phone (Xperia L1) but I can not reply to 1 contact who has texted me. I have no issues receiving and replying to all other contacts at present.
I have tried deleting the contact and re-entering their details, I also deleted their inital text. But still cannot reply or send them a text message. I do receive calls both in and out to them. I had no problems replying to them on my old phone (Nokia) Please help!