a particular contact is not receiving my text messages. I believe this is happening since the upgrade to IOS7 however not 100% certain. Funny thing is this person can text and I receive the message I replied back straight away and the message was received. Since then I have text 4 times on different days and the message is not being received by the contact. I am not aware of other contacts in my phone with the same issue. I have messaged other contacts regularly and not problems. I have deleted this contact and then added to contact list again but the same problem. Any suggestions??