too angry to come up with one

After my post of last week about Standard Bank sms spamming me to increase the limit on a credit card that I don't actually have, the call centre has been phoning me last week and this to get me to increase the limit. I've specifically told them to stop contacting me, I don't wish to receive sms or telephonic marketing, but they flat out ignore me and keep harrassing me. How inefficient are these people?