Why spamming is not an option in SMS

Today SMS ringtone can be listen more compare to ringtone. why???these days companies are very aggressive in marketing by sending SMS. Sending SMS almost make sure of user see at least once..but sending by mail does not serve their purpose.

In case of e-mail, they either block or spam so that in block status, they will not get even a single mail but in case of spam, they can see but they prefer empty it soon.

I want to know, why there is no spam option or any option by which user can have ways to stop getting SMS from these website.

Having un-subscribe option can serve a purpose.

I want to know why there is no provision in constitution so that these type of crime can be stopped. I am a victim of this crime so I pledge to TRAI that make some laws so that we people can be saved from all these spam.