Momentum don't want to be paid

I was insured with Alexander Forbes for about 20 years and a few years ago they were taken over by Momentum. I have always paid my insurance premiums by direct deposit. This year, Momentum advises me that they are only prepared to accept payment via debit order. I do not sign debit orders as i had a bad experience with debit orders in the past. I have offered to sign a stop order or to pay via some other method by Momentum are not prepared to accept this. This has gone on since July this year and is now jeopardising my insurance cover. There has never been a problem with the payment of my premiums in the past. I am certain that if I offer to pay via some form of legal tender, then it is ******** for Momentum to refuse to accept this. I look forward to confirmation regarding how I can pay my premiums.