Cannot cancel debit order

After subscribing to moneyhubs daily newsletter in November 2014 I found the newsletter to be sporadic and not useful for my needs. I have been emailing themoneyhub since January to cancel my subscription however to date have not successfully made contact however the monthly debit order continues to come off my account each month. I have even contacted the main person involved however she just ignores all messages despite not newsletters in the last 2 weeks being sent.