I'm seriously not trying to call you a liar, but you have no way to prove it definitively. And if it's with two different strains, that tells me it might be something you are doing. Try germing them longer, if they haven't been drowned. With a little warmth and wetness and extra time, they will likely pop. But I am positive it has nothing to do with Midweek Song.
What pisses me off about this is you guys are slandering a reputable business, and you really don't have any 100% indisputable proof that it wasn't you, nor that it was them. And of course a lot of growers are proud and don't want to admit the possibility that maybe they made a mistake, but that is even more of a possibility than the seedbank, rather than the breeder, being responsible for your seeds. The seedbank can't pop your seeds to let you know their viability, they just get the stock they are sold. Want to ask
@Midweek Song if it's possible they sold you old stock? Let's see what they have to say.