Have not changed banking details since December

I sent through a request to Menzi in December last year to change my banking details, with all the forms filled in. Then this year comes, I get a call from Shane saying Im not covered anymore because I havent paid for two months, but infact they never updated my details. Then Shane says I should send him my details and he will do a debit order. Week later and I get a warning from Vicky that my insurance will be terminated if I dont pay. They have all the documents they need but no I get *****ed over and I have to fix it. They dont even reply to my emails anymore.