no response from cell c retentions

I have been emailing your retention's department to cancel my contract because I can get a better deal with vodacom on the phone I want, the retention's department is clearly not interested in retaining the customers but is also not confirming the cancellation of the contract, Please advise the final payment and that my contract will be terminated on the 30 june 2016 whereby the number will be made prepaid so that I can port my number when I get the new contract. Please do not loose my number ( like what cell c did with my wifes number Pieter ***