Merrin Shards

Ever since the last update was released that gave us the option to purchase Merrin shards for crystals in the store (4,8 or 16 shards) they have appeared once (I purchased 16 shards). I have checked every reset throughout every day since the update and she’s only been available that one time. I’ve also done numerous refreshes using crystals in the hope that I’d get some more but sadly not. Is anyone else having problems getting them? (And yes I’ve already exhausted the supply in the weekly store)