Guardrisk Debit Order ****

I am getting debit orders from guardrisk insurance, I tried calling them to sort this out but there was no answer and again this month I got debited and I have never signed up for anything and for some reason I can’t even reverse the debit orders as it doesn’t allow me to, which screams *****. It’s quite shocking at how guardrisk an insurance company can come into our banks and take our money without authorisation and yet when you call to sort it out and enquire they don’t answer their calls