MMS issue

[MrsDebbi]

My problem is One particular contact (person x) which I send a text message to ALWAYS changes to a group message.
I can not figure out how to stop this from happening.
I have deleted the contact (person x).
I have deleted all contacts that appear in the group message (persons C,D & E).
I have uninstalled all messaging apps.
I reinstalled an entire new messaging app.
I ran the MMS fix-it script.

I can however, begin a new message every time I wish to chat to Person X and it will send only to Person X. But as soon as I go back to the list - the message shows up as a group message to Persons C, D, E and X.
Any incoming messages from Person X post to that group message, unless I catch it at the Pop-Up stage.
Person C, D & E will receive as a private/individual text as it should normally do.