my moto metals looked WAY better than that after almost 2 years, I had a dog piss on two of them and forgot to wash them til like a month later I see this green corrosion lookin sh!t in the formation of trickles and realized what it was from... washed it and continued to wash them for the last year and a half and they're no where near that bad... I live in HI and drive right up to the beach sometimes and don't always wash the salt spray off for weeks... road salt in 3 months on 8-9 month old rims shouldn't do that imo... look at the thickness of the chrome... I don't personally think their black wheels will be much better only because it's probably a similar paint thickness
good luck though! and I hope you get a new set. if you can sell um and buy something else if you don't want the same thing repeating...