Amazing Vouchers. How do we stop them?

I am having huge problems with a company called Amazing Vouchers. I have requested that they stop debiting my account for years now. They seem to stop for a couple of months and then it starts again. I have emailed and called them hundreds of times and this still hasn't been resolved. Not only is this completely unprofessional but this is costing me a fortune with having to keep reversing these debit orders. With regards to the below reviews, please note when the lady called to sign up for this, I was not informed about a cancellation fee and to be frankly honest, I don't even know what this company does. I have yet to receive something from them? I am so annoyed and frustrated. Amazing Vouchers, I urgently advise that you immediately stop debiting my account before I take this further. This is getting ridiculous now.