Vodacom are useless

A year ago my contract expired We have made numerous phone calls to cancel the contract but all they did was take the handset cost off the bill and continually debiting me for the 60 odd rand Every time we go into Vodacom centre they say that we must phone to cancel but when we phone they say its cancelled but it isnt secondly My insurance on my other line is for the wrong phone and Vodacom centre cant help