I totally understand the situation. My issue is with the attitude. There was a wrong estimation of delay. It happens. There was a wrong reporting of the items that were actually missing. First it was one, one month later, it was another. We are humans.
There was no "we apologize for our reporting mistake", "we will do all our best to avoid such mistakes in the future", etc. "although we acknowledge not having met the expectation, we cannot split on our cost, as it would be too jeopardizing to our business", "is there any other way we can be of assistance", etc.
Instead, and very dry: "you want was initially forecasted, you pay extra."
So, I keep with my notation. The attention to the client was minimum, to say the least.
PS - are the estimated delivery dates on the site already updated with the latest gained knowledge?
26.10.2021