S3 Mini picture messaging issue

Hi everyone . I have just got a S3 mini and so far i love it but when someone sends me a picture message it shows as a download. I cant afford to have the internet on so therefore cant get the message. If i send one it says it will send when i turn on my packet data?
I have never had to have the internet turned on before with any other phone to send picture via text so why now?
Can anyone tell me how to make it work keeping my data turned off like all other phones please