Sears review: diehard advanced gold

Purchased agm battery and carried home - no auto install. Found that it was totally discharged.
It probably sat on shelf 6 months in discharge state which degrades the battery. Charged it myself with a quality battery charger and left on float charge for several days. It would not exceed 12.7 v under no load. It would barely hold 12.0 v with 15 amp load.
This seemed low, but to check i bought the same battery from the same sears that had a good shelf charge. This battery tests much better; 13.2 v no load and 12.4 v @ 15 amps. Clearly they gave me a subpar battery but would not replace/exchange because it passes their "test", even though it was never used.
My god, the battery i traded in would pass their test. Passing their test, which mainly identifies dead batteries, shouldn't be the acceptance test for a new battery.
Reason of review: Damaged or defective.
Monetary Loss: $230.