Ploy to delay payment or not pay at all

On 19/01/2021 We submitted my surplus claim. On 04/02/2021 I followed up and got a replay saying that it was submitted 04/02/2021 and that I should follow up 2 weeks later. On 11/02/2021 I got a call from a very rude gentleman asking for an affidavit stating that my old bank account is closed after 20+ years and stating new bank account details. Also they now request stamped bank statements again and certified ID and proof of residence. The affidavit was never part of the original email received stating documents needed and all other documents has already been sent through to them on 19/01/2021.

I believe that this is just a ploy to not pay out my money or to delay it as long as possible.