Unauthorized debit order from 1life insurance company

I would like to complain about 1life insurance. I have a life cover with them and missed a payment I November, made an arrangement to pay it on the 6th of December and as per agreement they debited my account on the 6th. To my surprise on the 2nd of January 2020 they debited my account again, as if that was not enough on the 5th (today) they debited my account again for the 3rd time. Am very much agitated by this.