Nedbank keeps on billing charges for cancelled insurance

We have a Nedbank Homeloan, and it was covered by Nedbank Home insurance. In March 2025 I cancelled the home insurance, and gotten cheaper home insurance as the insurance at Nedbank just became ridiculous high, and unaffordable. From the start Nedbank Insurance has lots of stories, yet on the 14th of April I received the cancellation letter. I sent an e-mail to Nedbank Homeloans, informing them, and attaching the said letter. Yet to my surprise, I noticed that the amount claimed from Nedbank Homeloans was still the same, and I received a statement showing that an amount of R1114,17 was claimed once again 5th of May 2025. I sent the statement as well as confirmation of my bank details to be refunded, as this was cancelled! Yet now Nedbank is just replying, we acknowledge, and no refund has been made at all. It seems that Nedbank is just doing whatever they want, and money is being taken, and not being repaid! I want my refund asap. It also seems that Nedbank Homeloans and Nedbank Insurance, are not able to communicate to each other.