Strange, Corsair uses Seasonic units but Corsair's customer service is legendary. They treated me like a king! I initially bought a corsair platinum based on my excellent customer service experiences with them, but their platinum model had coil whine, i couldn't bear it! Went back to the store & exchanged for another corsair... but 2nd one also had coil whine! Went back to store & exchanged for a seasonic platinum & no coil whine (but seasonic one cost a little extra). I read the seasonic used extra glue in a certain area & that eliminated the coil whine.... or maybe it was just bad luck with that Corsair batch.
Anyways, OP why didn't u just go back to the store to exchange it? Most stores have 14-30 days refund/exhange policy in North America for defective products. No need to RMA the first 2 weeks atleast.