Apple doesn't need to get involved. It is really a problem of Verizon's own making. If they want their employees to sell more iPhones, they can eliminate the spiffs or they can pay Apple a few Billion. Their choice.
This is exactly why Tim Cook wants potential customers to go to an Apple Retail Store. Apple doesn't want to pay spiffs to BestBuy or Verizon employees. Why do that when Apple specialists will do a better job for free(or at least close to it)!