overcharging and non delivery

I signed up for a subscription in August but only started receiving newspapers last week of October. On 15 October, my bank account was debited for R81,24, on 15 November another R48,75 and 15 December R32.49. This is despite the fact that there was no delivery on 6 December and none yesterday as well. I called last month to cancel the subscription and was surprised that my account has been debited again. The amounts debited compared to the months I have received the newspapers does not make sense as well. I have called so many times to Sunday Times to try and resolve this and am getting nowhere. I need this subscription cancelled please and any monies due refunded to me.