MTN *****ing my money for over 6 months now and won't help!

For over 6 months now my cell phone account is being debited with unauthorised SMS's that I am not sending. I am overseas, so I am paying even more for these SMS's. R1.25 for each SMS to "45411". MTN simply do nothing, they keep telling me they have logged it and will come back to me once they have feedback but I never hear from them again until I follow up, at which point I get the same reply. They tried to suggest this is a subscription service that I signed up to, but I never signed up to anything and checking my subscription services shows no active subscriptions! My money keeps being ****** and MTN keep doing nothing, it is absolutely shocking treatment of a customer. I had an email from "Brendah" in the Complaints Management Team once however she doesnt reply to any of my emails now. MTN you're a disgrace...