Vodacom unending contract

<p>Your customer service has failed to make me understand why when i enter a 24 month contract and the period comes to an end, the contract does not end. It seems logical that a contract ends at the time that is was scheduled to end. So when i continued to recieve billing i questioned it and was told i must cancel it verbally and i did except that apparently the person i was speaking to only cancelled annumber i didnt know and that i had been paying for for 3 years. So when two months later i my line is suspended because i have an outstanding amount, i am shocked because as far as i know i am on pre paid and have been paying my way. I call in and am told i am still on the contract i cancelled 2 months ago. Is this a trick to keep us paying?</p>