Credit life cover cancellation struggles

I have been struggling to cancel my credit life insurance on my personal loan, I had a form for instruction to cancel filled and emailed on the 28th August 2018,with reference number ********** 1 and ever since then it hasn’t been cancelled and I haven’t received my refund as they have debited with the monthly installment, u emailed over and over and with no response, then I called then they say I need to go into branch to have this done, a cancellation, so today the 14th September 2018, I had the same form filled in at branch to cancel the life cover, what is the difference between me emailing the form and their own employees sending the same form? I feel like they just want to delay so they keep taking the extra money, which is over 600rand a month, can this be resolved please? Sad how we need to struggle to close things off but when they want their money they call you like there is no tomorrow, once again I have to wait until next week Friday to see if this has been done, the cancellation of a life cover for my loan,