Direct Debt - not connecting to bank

For the past 3 months, I have attempted to move my iDmobile Direct Debit from my personal account to a new bank account. I can see the bank account information on the iDmobile app but it never arises on the bank app on their list of Direct Debits to be paid. Each month at payment date, I get a message from iDmobile saying that the receiving bank has no record of this DD and therefore cannot pay. I am forced to make an emergency payment with my credit card. I have spoken to the bank in question, and, in their experience, this happens when the Direct Debit establishment request is not actually submitted to the receiving bank by the vendor in this case, iDmobile. Could you please advise me on this and preferably provide me with details of someone I can have a private exchange with to resolve this issue?