Discovery Life unfair approach to a change of banking details

So, I changed bank account, with same bank. My bank reached out to all companies where I have debit orders. Discovery Life did not respond. I logged onto the self service portal, and added my new banking details (official bank confirmation) etc. Weirdly I saw email that they could not reach me. The next day I got some form to fill in. The next day by the time I submitted the form, my policy had been suspended, and now have a 30 days waiting period. All along my account has had money, lots of it. Never expected such from a brand like Discovery, and it appears I am the one defaulting even though I submitted my details onto the portal