I would do what SnoopZ has suggested asap.
Mark I did not think they are allowed to take a DD or Standing order out on a Saturday, what they may have done is reserved the payment this will show as a (pending payment) on your account.
I would also ask your bank if this company cancelled the DD then if they did not then I would phone the company and say you have now have confirmation from your bank that they in fact did not comply with what they said to you in cancelling the DD
therefore this has now put you into financial hardship as you did not budget for a cancelled DD and why should you after all it was meant to be cancelled. If you get no joy with the company then I would request that they email you stating as to why the DD was not cancelled when they clearly stated to you on date xx/xx/2016 that it would be cancelled and if they would be so kind and attach a copy of their policy in regards to refunds in regards to this matter that you now find yourself in
at no fault of your own and you find it extremely unfair that you are in this position due to their error. Ask them if they think it's fair that you are out of pocket due to their error!
Good Luck and hope you get it sorted soon, this link may of help Mark.
http://www.money.co.uk/current-accou...rules-faqs.htm