Worst service ever

My mom, who's a pensioner have been battling for 8 months with them to deduct a premium on a monthly basis. Every month it's a different story, every month she has to contact them to inform them the premium didn't go off yet again. All documentation was submitted in 2025 informing them of a change in banking detail. A confirmation letter confirming the change was receive from them, yet every month she has to incur extra banking fees to make payments because they did not deduct. After numerous calls, emails and proof of payments sent they are now saying the policy will lapse if payment is not made. She is gatvol and close to letting the policy lapse, because she is getting nowhere with them in 8 months.