I have brought this up in some form or the other. The response I usually get is something like "hey man, I understand this is stressful for you but their business depends on this" or "this is really important" or some empty promise that things will be easier after this feature is done. I have a feeling (might be wrong) that they want to keep this client because it pays a lot to our company (which is a little absurd to me but assuming a lot for our company isn't too much for them)