How to make a formal complaint against the DWP

I received an overpayment letter from PIP and appealed the decision. The case went to court, and I have a judge’s order confirming that I only owe part of the money originally claimed as an overpayment—not the full amount.

Despite this, the DWP has continued to deduct more money from my benefits than I owe and is still doing so. I am also receiving warning letters demanding payment for the full amount, even though I have official court documentation proving I do not owe this money.

I have called several times but have been passed from department to department without resolution. I understand that there is a new independent agency that can review cases when someone believes the DWP’s decision is still incorrect. However, I understand that before I can escalate the matter, I must first receive a formal written response from the DWP regarding my complaint.

Does anyone know were I should write to in order to receive a written formal response from the DWP? I have found conflicting information and incorrect contact details online and I am confused.

What is the correct procedure to ensure that my complaint is properly logged in the DWP and that I receive a written reply?

Thanks Jacob