Billed wrong price for international calls

Hi<br> <br> I have noticed that I have been charged the regular price for international calls despite the fact that I have been receiving the SMS monthly to tell me that I have subscribed to the international Plus rates at R5 per month<br> I have had not luck getting anyone to help me via Email, (case keeps getting closed), call centre (when I call they either don't answer or hang up when they cant answer me) or twitter (no response) please HELP!