Unable to cancel unrequested Standard Bank SIM card

I have been trying to cancel my Standard Bank SIM card for almost a week, but can't get through to consultant on the bank's helpline. I never requested a SIM card, nor did I ever activate it. I have been charged almost R90 for a product I have never used. I feel like this is really sneaky as I wouldn't have noticed the charge if I didn't check my account debits every month. Makes you wonder what other funds the bank deducts from customers' accounts without their knowledge. I feel like the debited amount should be reversed as I never wanted or used the SIM. Really disappointed.