It is comforting to know that others have had similar file problems as well. Certainly it is bound to happen, particularly for those of us who download many books.
Yes, it will be sorted out eventually but my point in posting (and complaining) is that the vendor should be prepared to resolve such issues quickly and, at the very least, respond to the customer ASAP but, absent an advertised phone number, that apparently is a low priority. The customer should not be the one wasting their time and jumping through hoops.
(and there went a perfectly good coupon down the drain)