Still debiting my account after cancelled contract, refuse to refund and no help to be found

I had great service from Connected space for 3 years, then when time came to cancel I followed the instructed steps just to be caught off guard for another debit order a month after moving out. They now say even though I followed their instructions , if I did not receive confirmation email (nowhere did it say to expect this), I am liable for this charge and they are still refusing to confirm my account has been cancelled. I have found this to be a terrible customer experience.