Mac keeps receiving replies to sms msgs even when imsg is turned off on iPhone

Hi

I do not use Imsg much and I have it tuned off in mu iPhone. However recently whenever i sms someone, their reply does not show on my phone and later when i access my mac, their msg is in the messages app. Im guessing this is because of some sync but I want to get my msgs on my phone as I don't access my mac till night when i sleep. I just want to send and receive sms txts from my phone and not have my mac involved. Please help.

Best

Ash