I quite agree. Apart from the fact that they are wasting their budget (a.k.a. our money) on a company who are not delivering the service paid for, what about the poor people who are relying on them
Not everyone has a Lardman who is there to fight their corner, wade in with hours of help or pay for more out of their own pocket. I dread to think how they would cope with such ineptitude.
Never mind finding someone to blame, who has left and then can't be blamed and sending you 12 pages of reasons it's not their fault - what are they going to do in the here and now to fix it and make it right. Complaints are there to be dealt with, resolved and learned from, or you may as well save some wages and get a computer to automatically issue excuse letters
I would be trying the ice cold polite but firm 'who, what, where, why when' approach. I'm sure you already are Larders, but just cheering you on from the sidelines