MTN unable to correct a minor issue

My wife signed up with this "service" provider some time ago. We filled in the application form with our email address, which begins with a T. Subsequent to this my wife receives a message every month which states that the statement and balance has been sent to the following address, and the address begins with a K. We went to the local MTN store to try to get this rectified and the agent told us that he could not do it in store but had to raise a ticket. We have just received the exact same SMS with the exact same error. Phoning the "Customer Care" number, which is automated is completely pointless as the call is dropped before one can complete it. MTN survives only because the other service providers are equally as useless.