Still deducting after cancellation

I cancelled ADT on the 3rd of January 2014. Alarm was taken out and after a year my account was still active on their side. I couldn't stop the debit orders at the bank because they change the reference number every month. Eventually after a year and numerous calls, I got conformation on the 11th of February 2015 that my service was cancelled. I keep on phoning for my refund for premiums paid over 12 months.....everybody promises to phone back but they NEVER do! And to top it all off they deducted again on the 26th of February 2015. WORST SERVICE EVER!!!