Bank verification delay

Changed my banking details about two months ago. I wasn't notified to verify anything until I was due a refund submitted the documents immediately. Been getting notifications to upload banking verifications for weeks. Now according to you it takes 21 days called in today was told the documents I uploaded were wrong. I went and reuploaded now I got off the phone I'm bieng told its another 21 days. Which I do not accept. Firstly I wasn't notified to verify details when I changed them prior the seas. Secondly. I waited almost 21 days after uploading to only be told they aren't correct after I had to call in. Now I'm told to wait another 21 days. I submitted another complaint. And guess what the turn around time is another 21 days. So either way for the document upload or complaint I have to wait am additional 21 days when I changed my details week ago? Absolutely bull. I want this sorted Asap! I want my money! Case ***