Imposable to cancel vodacom insurance

Last month I wrote a review on this site regarding the incorrect billing on my account, I received a call from Vodacom but Wow the bill is still incorrect I am frustrated with their services and I curse the day I agreed to an " downgrade updrade " ..I hate that service provider will not even recommend it to anyone . I have been trying to get my insurance cancelled for months a contract phone which was supposed to R189 a month to being charged R238 every month the bill differs yeeerr! Your staff is *********** .