incorrectly Charged and no one actually assisting to rectify

*i have cancelled my mobile insurance in September with telkom insurance ,i received an Email advised the policy has been cancelled ,i was advised that the last debit will go out , the last debit then went out at the end of September which was unfair as the policy was cancelled at the beginning of the month ,but i looked passed it ,Now i have been debited again in October ?? then i received my bill for the end November and i see that im still being billed for the insurance ,i called so many times to get my reimbur*****t and to get then to stop charging me and i am placed on hold and only having calls dropped , i then speak to a few people who advised they will sort it out and call be back (to date nothing as been done) i have sent so many Emails and still no response ..

all i want is this problem to be rectified is that so much to ask for ..i have proof that the policy has been cancelled via email response ,why i am still being charged ???