You called? We did put a lovely disclaimer of "copy-pasted from JP sources that did an estimate during their event".
Assuming the drop rates are correct, then your misfortune so far is about 1:200, which is still less unlikely than getting a black from a base SP summon.
There is enough RNG involvement in this game that everyone is going to get unlucky with *something* - e.g. Crystal Keeper hates my guts, but at least I don't have a Conrad curse.