Unfair customer treatment

I've had a life cover with discovery since June 2016 unfortunately the previous month I was unable to make the monthly premium payment. I received an email that it was in arrears and that I should call to make payment arrears bare in mind that this is no debt but a policy. I called in on the 31st to make an arrangement but was told that they are not able to make the arrangements because they had already activated a double debit on my personal bank account which I did not consent to. The email sent states that I can arrange to pay arrears in installments and it did not state that should I not call by a certain due date they will automatically activate a double debit of the full arrears amount. They chose to deduct the full amount without making prior arrangements with me or getting my authorization or approval. The treatment I have received from discovery is less than desirable. The only correspondence I receive from them is when my money is concerned. The consults I spoke to where of no help and the manager was even worse. Not the most professional, didn't even know the history of the policy and lost her composure during the call. She wasn't acting in the best interest of the client being me instead she was just reiterating the fact that they have already made a decision on my account and she can't help me. From my last hello peter review my account still does not have a financial advisor. To say that I am a customer who has been treated unfairly would be an understatement. Since 2016 I have received no joy with this policy and the thought of canceling this policy and losing 8years worth of premiums is devastating.