Cat in Vet thanks to flea drops

I have used the Hartz flea drops before with no problems on my 15 year old cat. I applied it this past june 30 2016. Next day she was vomting blood. Took her to the vet. She is still there on IV’s, Vet giving her laser for the neurological damaged she suffered because of the poisoning. My heart is just broken because of this. Why is this product still on the market???

Ultraguard Plus for cats

I bought this for my cat who had fleas. It took the hair off of her back and made her sick. It also did not kill any fleas. So disappointed in this product.