I am astonished at the moderate tone of the contributions to this thread! Surely this is a tale of quite monumental incompetence compounded by neanderthal customer -awareness and -service skills.
You should be seeking, as much more important in the long term if they want to keep your business, an admission of this and an undertaking that there will be put in place processes to prevent a repetition. Of course the requisite financial compensation is clearly due as well.
