been working on this lately too...
I'm not sure contacting customer is a great idea. Better to find the best re-billing profile. Like: Hit the card on alternating days, again on a few billing anneversries, try hitting for 1/2 price, etc etc...
It helps to have a processor or gateway that will let you experiement easily with different profiles. Different strategies seem to work for different customer types and different sites.
It's rough out there these days.
