Everything listed in "Messages" results in Options, Settings, SIM1 message center and the phone number. The phone number currently shows +447958879890, but may have been a different number when it first showed and has now been amended. Consequently, "Messages" is now unusable for writing and anything incoming and outgoing. Phone calls to 789 have so far not resolved the problem. No point using the Text Messaging Service. I could send a message from "Contacts" but would be unable to read any reply.