I thought that one had to be accepted as a contact; before that person could become a contact. Is this true?

I never got any word back but I was having that issue too. My only assumption is that they are fake (bot) accounts trying to gather information from members. Last month I had I think at least 5 random accounts suddenly become connections of mine. Never heard of them, they had no picture and most of them were labeled as civilian recruiters. When I went to their profiles I saw they had added hundreds of RP members in a very small amount of time.

I haven't seen any since last month but if you are still having an issue with them then I would suggest notifying an RP Admin of the issue.

From my experience, that is the way it works