MTN is taking my money and not giving me what I am paying for

I was contacted by MTN to upgrade one of my accounts which I accepted. This meant double the data and a R40 increase on the contract. MTN have been debiting my account but I have not received the increased data as promised. I have called several numbers and when I finally reached a person I was told to contact a different number none of which have an option to either deal with my issue or talk to a human to assist me. I am fed up. I have 4 MTN accounts and I am ready to cancel all of them and move to another SP. It is Extremely frustrating not to be able to speak to someone who can assist. All I get is an automated voice response and no options to deal with my issue, I NEED TO SPEAK TO A HUMAN WHO CAN SORT THIS OUT!!! Regards FRUSTRATED