"Understaffed" may be their only excuse, but it doesn't absolve them from responsibility. They took money to provide the service. If their claim is "we took your money but didn't use it to hire people to do the work" -- what kind of excuse is that?
And exactly how long does it take to copy data from one place where they put it on the form, to the place the FDA asked them to put it? How understaffed are you to not put dates on the patient data?