Layer's Crumbles and Layers Pellets will both contain adequate calcium and nutrients for your girls. The crumbles (which my birds prefer to pellets too) are just the pellets crushed down to smaller sized pieces. So whichever your birds seem to prefer is fine.
I used to say that my birds didn't like their crumbles either. The thing with chickens though is that they will eat any other feeds offered before they will eat their crumbles. So if you feed vegetables or table scraps or scratch or wheat, they will always eat that first and leave the crumbles sitting there. Why eat the crumbles when they know other treats will be forthcoming?!
The trick is to take away all other food sources. I know that's easier said than done, because it is so lovely to sit out in the run with them and throw a handful or two of scratch out. I put it under the heading of "It's For Your Own Good" and just take everything away but for the crumbles. They may get cranky and hold out for a day, but when you don't show up with other tasty treats, you better believe they will learn to like crumbles! Chickens are all about the food, so it won't take long before they start scoffing it down.
ETA: If you really think your girls don't like the crumbles you are feeding them you could always try another brand. I think there are a few brands of crumbles available so perhaps switch over to another brand and see how they go with that....
- Krista