Sounds like maybe someone didn’t read the small (ok, not that small) print about relative power of classes in Vanilla. Or maybe thought they were going to be the first guy in 15 years of people playing and thoerycrafting the heck out of vanilla to discover a miraculous way to make a MEME spec be suddenly amazing. Either way, you got what you paid for.
Look, I feel your pain. And in actual vanilla, you would have an argument. But this was an open book test. A 2 min google search and read would have let you know what you were in for… PEBKAC?