Chop (2011)

Random car trouble and aid from a good Samaritan aren't what they seem, much to ex-drug addict Lance's growing horror. Retribution for a past injury is the name of this peculiar stranger's game as he violently, callously and torturously dismantles Lance's life bit by bit. Desperate yet unsuccessful, Lance tries to recall what harm he brought to this particular man (which will end this game), confessing to other misdeeds that prompt his tormentor to seek out and retrieve the injured parties to share in his vengeance. With body parts running out, it's a wonder if Lance will ever recall the correct transgression that started it all before only his life remains.