SMS going to random number.

OK, so I was texting a friend and after a while I get a response "Who is this?" Later on found out it was some random person, but when they responded it was under the contact's name. I doubt it was a prank.

I tried 2 other people and messages went through fine, but they are on ATT too. Where as the person I was texting before is on VZW.

This might just be a carrier blunder. I'll try again tomorrow.