Lack of response and no answer at relevant department

The accounts / collections department is completely unreachable. I just held on the number : *** for 58 minutes and 43 seconds before the line automatically cut. I have a picture as proof. This number was given to me by the customer service department. There is no response to emails since the 7th to various addresses. Customer service department cannot assist with the request either. I have power of attorney to obtain information on behalf of a mutual client but even that is disregarded. All that is needed is a paid up letter. If this is the case, I can't imagine how actual clients get 'service'.