Double insured since September 2020

I requested a cancellation on my policy on the 11th of August 2020 - informing AG that the last day of cover should be on the 30th of August 2020. Last month I went through my banks statements and saw that my account was still being debited with the AG debit order. Effectively I was double insured - which I believe is against the law. I reached out to AG and got in touch with Mandiluve Mbomba. She was a great help and after I sent her proof of the cancellation made on the 11th of August 2020 - the debit order on my account was cancelled. I've reached out to Mandiluve about the repayment of the premiums since September 2020 - but to date I've had no feedback.