Breach of Confidentiality!!!

I have had a Vodacom contract in my name since May 2011, that's over 9 years. A few minutes ago, I placed an order on the Vodacom website for a Fibre internet deal. To my horror, when I completed my order, the website said that confirmation has been emailed to ***, however this is not my email address! I firstly want to know where did Vodacom get this email address from as I can assure you 100% that I never registered this as my email address. Can someone senior from Vodacom investigate and get back to me ASAP as I feel that my personal information has been breached and I am really concerned and angry, I will be contacting the relevant authorities about this as well so Vodacom please ensure you contact me with a proper response. Secondly has my order been received and processed?