Mtn does not respond!!!!!

I tried to contact Mtn regarding a query on my account where I thought I was being charged for calls I didnt make. I called their call centre 6 times and was cut off each time after holding on for more than 5 minutes. I wrote to their customer service email, to get an automated response to say it would be dealt with within 5 working days. After 6 days, I get an email to ask me for more details to prove that the account is mine. I respond immediately and am waiting for a further response I have now waited an additional 5 days and have not received a response. I sent a web based query to them over a week ago, I have not had an acknowledgement. I wrote a report here (to hellopeter.com) as Mtn is a company that responds. Well they dont, as it is about 10 days ago (I cant remember exactly) when I wrote my first report and I have not heard a peep from Mtn. I am currently travelling overseas, so i have requested that they communicate via email. Surely this is not too difficult. What can I do to query my account if I get no response from the call centre, email, website or consumer pages. PLEASE HELP, I HAVE RUN OUT OF OPTIONS!