Why don't yo ureplace it iwht something native that may be happier in that spot? White Kisment echinacea (cone flower) is very similar to shasta daisy.

Are they in full sun? How's the soil and water drainage?

Are there signs of aphids, slugs or other pests? They love shasta daisies. Are you putting them in the same spot every time and refeeding the bugs?

I have never had luck with these. They either don’t grow above 5 or 6 inches or don’t bloom at all.
I just planted some 6 inches round daisies in yard. They looked healthy at the store. Tall with buds. Now they are completely bent over. I have watered them. The weather has been perfect and they look half dead after a week in the ground.
Any advice?