VODACOM UPGRADED MY CONTRACT WITHOUT MY KNOWLEDGE

I had a contact with Vodacom where i took modem and a laptop, the contract was supposed to end on the 27th February 2015 but instead they decided to upgrade my contract without my knowledge. All they came to me after they deducted money from my account and i went to Vodashop to enquire why are they taking my money now whereas the contract has ended that where i was told they upgraded the contact. They then send an email to their Head Office where i was informed that they will reply in 5 minutes time and i have not yet got any response from them up to date.