Netflix complaint: Overpayment cancellation of account

I have been overpaying for 4 months. Netflix have charged me £11.99, twice, for 4 months. I called and was told that they wouldn’t refund me for all 4 months, just one month, and that I would have to contact my bank that Netflix would cancelled the fraudulent account on my Netfilx account. The customer service is an absolute disgrace. The operator was just constantly talking over me and not letting me finish what I was saying and I called and spoke to different people on 4 different occasions.
I called my bank they have had to send me a new card. I called Netfilx again they have told me that my account with them has now been cancelled, I didn’t ask for this, I told them that I have just been charged for this month (July) and now I can’t use it. But they are now refusing to refund me this month, so I have paid for this month but unable to access it.