Vodacom does not want to cancel my contract

I was due for an upgrade but i decided to cancel my contract and be on prepaid instead. I emailed vodacom customer center and they did not respond. I went to a vodashop in fourways and The Grove mall and they provided me with the following numbers for contract cancellation. *** for contract and *** for insurance. The lady on the phone on the 14-April offered me a deal of R139 for R200 airtime every month and 1GB. I thought it was a good deal but later when i logged in in the website i realised she had **** the contract was going to const me more it was going to cost me R229 pm. I called in the evening to cancel the whole deal altogether but the other lady told me to call 1st thing in the morning and get it cancelled. I called in today (15 April i am reffered by one lady telling me she is cncelling and she puts me on hold. later on as i was holding the line the other guy asks me to repeat the same details i had told the previous lady and i had asked him why do i have to repeat all the details and he had said he does not know. He puts me again on hold and i was holding for more than 30mins. i ended up dropping the phone as i was not using my phone number at the time.