warranty replacement an already replaced ac delco battery?

[apollo18]

hey guys! in my truck i purchased a new ac delco battery with 42 month free replacement warranty in the end of 2014 because my old battery was out of warranty i assume.
in early 2018, this ac delco 79pg battery stopped working and i took it to the gm dealership and they replaced it under the 42 month free replacement warranty with another ac delco 79pg battery. now in 2020, the warranty battery stopped holding a charge and i took it in and they tested it and it failed on the spot. but they said they cant warranty it since the warranty starts for the original battery which was in 2014.

is this true? or are they trying to get away with it?
in my opinion since the 2018 battery is the exact same battery and has 42 month warranty, it should have warranty starting from 2018 because thats when it was installed.

i was thinking of just taking it to a different dealership and and not giving my vin and hopefully they just base it off of the date code stamped on the battery? any tips on if i am eligible for a replacement an easier way?
thanks

[StinkyCheese]

Warranties usually start from date of original purchase.  If something is replaced under a warranty the warranty usually does not start over.

[Z45]

^ This is typical of replacement items under warranty, its never starts over.