worth asking anyway... but if they demand the pair back and only offer a refund, you're losing money over keeping a single stick probably.

to add... (mainly for the benefit of others who may come across this)

most ram, purchased new at retail from a legit or 'authorized' merchant or store should be covered by a manufacturers warranty. those sellers on amazon marketplace with random 'kdfguuugggu' names probably not selling warranty-eligible products. you would more than likely need a proof of purchase receipt to show when and from where you purchased the ram.

if it was in a prebuilt or major oem (dell, hp, lenovo, etc) system you're usually at the mercy of the builder and its system warranty. if purchased direct, the seller should have record of the system purchase. if purchased at retail, same deal as above--need the receipt.

if the ram was acquired as used product, you're probably out'a luck.