unauthorized debit order

Onair TV company processed an unauthorized debit orders from my account just because they have access to it. Since i took up a contract with them I have never missed a payment I have my statement to confirm. Getting hold of them is impossible I have tried emailing (***) (***) and calling ***) with no luck. I have been inconvenienced with a financial loss on my bank account paying for reversal fees worse of all they go and debit on the 1 May 2021 an I get paid on the 20th of every month and no one has called me to explain what is this debit order for.