If they're REALLY finding corpses turned around in their caskets, hasn't the thought that they might be burying their loved ones prematurely EVER occurred to them? Maybe they should wait a little longer to plant the deceased ?
In poor, remote villages where most people probably still die at home without a medical professional in attendance, no diagnostic machines, no autopsies, and no elaborate (and expensive) embalming practiced, one could see where that might still occur.
As for the business of digging up a supposed vampire, burning the heart and drinking the ashes, this was actually practiced in rural areas in THIS country even until the early 20th century, a charming tradition imported from the motherlands. But mainly as a cure / preventive of "consumption", tuberculosis, which was one of several diseases frequently mistaken, by the superstitious, for the condition of vampirism.
L.