MochaRaf

How about a simple form letter stating that <insert name> has taken and successfully passed a CPR course as administered by <agency>. An official card will be forthcoming. Please accept this note from the instructor <insert contact information here> as proof of having taken the course until an official card arrives.

This has been done by instructors with whom I've worked. To my knowledge, it has never posed a problem.

That is exactly what my CPR instructor did when my old one ran out and I needed it for EMT re-cert.

Unless you have forgotten every single thing you have learned in your initial class, I advise you don't retake the entire class. Contact NREMT or your local state EMS authority and ask them about the availability of a 24 hour psychomotor refresher course.