If you bank with same bank as your mortgage, then even cancelling the DD to the branch and the mortgage company, in my experience has little effect.
If that is their policy, then unless you do something, this will continue to happen so you will have to do make a decision to either pay it or open an account elsewhere.
We have literally had to open a new bank account and transfer every thing to it-all DD's, SO's, payments, online visa debit transactions etc etc.
Has been a serious pain in the..but now they CANT take it. I dont trust them an inch. They will leave you short and if they did it once they will do it again.
However, I dont understand why they wont do anything to help you.
Have you submitted a SFS (standard financial statement) either in writing or by phone? If you did, then only reason they wont engage is when it shows you can afford to pay your mortgage.
If you are sure you cant afford to pay, are your figures ok? Mabs website has lots of info on help with budgeting-I thought I knew how to budget but realised that I was calculating stuff wrong and not allowing enough for items that are only bought at certain times-firewood etc.
Do you have other non secured debts? Can you try and deal this other debt in meantime? I paid more to my credit union than to my mortgage company for over a year thinking it would be short term and kick myself now that I didnt prioritise my mortgage during that time.
Maybe completing the form on here would help the others see where the problem lies. If bank wont engage with you and you are sure that they should based on your income/outgoing level, then you can and should appeal it.
Good luck, its not easy I know