Replying to Texts being sent to the wrong number?

alright, so my brother texted me, and i replied to his text by hitting reply, making sure his name and number are in the "TO" box and pressing send.  A few minutes later, i get a text from a number i have never seen before, and this girl is bitching me out for sending her a text because she doesnt know me.  Apparently, even though my phone says the reply i sent to my brother was successfully sent to his number, it got sent to this girl's number instead, and the numbers are completely different; they even have different area codes.  Im thinking about going to the verizon store to see whats up, but the closest one is 30min away, so im just wondering if this has happened to anyone else?