Stop sending me post and stupid sms's

I have never ever dealt with this company i have at no stage opted in for you stupid post and sms's i have opted out many times yet you still spam me with sms's the final straw was when i recieved an sms this morning again and opted out AGAIN only to get more 2 sms in 5 minuites remove my number off you lists or i will have to escalate this further i even tried to call your call centere who does not even bother answering DO NOT CALL ME JUST LOOSE MY NUMBER