Ive had this before. Cancelled myself with online banking weeks before its due, and with the company. Lo and behold it comes out again the next month at the usual time.
I phone the bank and they claim it was never cancelled even though it was!
In the end i proved my case by knowing the exact time i logged on and cancelled it, plus showing them a print out i had made a few days later of all my DD'd when i was checking something else ( it did not show of course as it was cancelled ).
It seems to be that even if you cancel it at your bank AND the company, if the company decide to try and take it anyway the bank just pays up. This is totally wrong in my opinion, if a DD is cancelled with the bank by the customer that should be the end of it, if the company tried to retake it then it should just be declined.
If either of end of a DD is cancelled it should not be paid out- end of story. What actually happens is the banks just pay out and wash their hands of it.