This happened to me last year also. The plants never took off. I think the store life is hard on them, then moving puts them in shock. Adding all those "cide" chemicals may not have helped as they stress the plant too. Plus, like antibiotics, if you don't have a specific problem you are treating, don't just use them as a blind "vitamin" - they don't do the plant any good and over use causes resistance.
Keep them very well watered, give them time. You might get lucky and they'll recover.
That is all mostly a guess based on what you posted. A picture of the plant would help be more accurate.
Also, welcome!
