Pathetic service

I have sent an email on 23 October 2021 to *** to update my bank details with all documents attached. I have received no feedback just an automated message that gives me a number to call. I called the number and was advised by an agent there is nothing they can do because i can't be transferred to the admin department. I was told to send another email to give them a convenient time to call me which I did on 28 October and to date i have not received a call or an email. How long must i wait to just have my bank details updated