Very poor service

On the 4th November 2020, I completed a change of banking details form with Citiq and attached all requested documents. I was told they are busy with payments to clients and my request would be processed after the 7th November 2020. I sent them a reminder on the 11th November 2020 and it was confirmed that my banking details have changed. Citiq then paid monies owed to me to my old account which I was in the final stages of closing, all that money was used up by bank charges. How can they pay into an account which I specifically asked them not to? Unacceptable, very poor service and they don't even want to take responsibility, the consultant is blaming everybody but himself. Pay me whats due to me, into the correct account as I initially requested, what is so difficult about that...