It doesn't look to me like those leaves are wilted. It appears that you're growing them under artificial lighting and that the newer leaves have begun to shade the lower ones from the overhead light source, which appears to be a spot light . As a last resort, many plants curl and twist their leaves in an atempt to find the best possible angle to catch light when the light source is limited or blocked. The affected leaves won't go back to normal and will usually just fall off if they can't find enough light in their curved or twisted states.

I didn't know that. I'm new to this. I got this diablo mix for free from the nursery cause its super hot on south Texas and they were dying. I managed to bring 4 of the 6 back from almost dying. I supposed I'll need more light. I live in an apt and don't have much full sun available. The light was my next option .

If you want to experiment with more lamps, I'd suggest staggering the lamps at different angles so that the light reaches the plants from different points and hits them on all sides. Also you may want to water the plants in the shower so that you can rinse the leaves (especially the undersides of the leaves) each time because indoors I'd imagine your dhalias would be prone to an infestation of spidermites otherwise.

Don't get me started on spider mites. I think my area that I live is prone to them. I've already had to spray it with neem oil. I tried zinnias too but the spider mites loved them. They loved my sweet potatoes vine too. I think i got them in time but the poor plant got it good. I will for sure get a couple more lights.