Why do my contacts seem to be sending texts from the wrong phone number?

[purplelime]

I recently switched to the galaxy s5 and created my contacts (connected to google) by hand since there were so few. On one of the phone numbers, I messed up the area code and later fixed it. However, now whenever this contact sends me a text message it appears to come from the wrong area code phone number rather than the contact, even though when I look at the "message details" I can see it coming from the right phone number.
I've tried deleting and remaking this contact as well as giving the wrong phone number separate contact details, yet still when I send a text to this person, their reply is grouped as if sent from the wrong phone number.
Any and all help appreciated!