The class action lawsuit was first filed against Apple in July 2016 by customers in California who were unhappy that their iPhones and iPads were replaced by refurbished devices under Apple's AppleCare or AppleCare+ plan.
The plaintiffs, Vicky Maldondo and Joanne McRight, claimed that Apple's decision to offer refurbished devices violate its own AppleCare Terms and Conditions and the Consumer Legal Remedies Act. From the original lawsuit: The Apple Plans purport to provide consumers with Devices that are "equivalent to new in performance and reliability." What that phrase means is 'new' as refurbished devices can never be the equivalent to new in performance and reliability. Plaintiffs allege that it means refurbished. Refurbished is synonymous with the term "reconditioned," that is, a secondhand unit that has been modified to appear to be new for all purposes relevant to this litigation.
Source: macrumors