Debiting instalment after I've canceled

I was a happy client of Old Mutual Insure for a few years, but now that I've canceled my policy with them, it's come with great disappointment. I gave ample notice to end my cover at the end of September, but they still debited the instalment for October from my bank account. When I questioned this with my broker, I was informed that they'll refund me the money but this could take up to 2 weeks. She then advised me to contact my bank to stop the payment because the money will then be back in my account immediately.

It amazes me that these companies are quick to take my money, but for them to pay it back takes 2 weeks. I find it very unfair that I (the customer that gave ample notice of cancelation) have to now do the extra work to get my own money back that they wrongfully debited from my account.