What’s a good flea treatment?!

The vet gave us frontline gold for our cat and it only worked for a couple days! We were finding dead fleas/seeing them die for about 4 days then after that just them alive everywhere multiplying like crazy finding more and more flea eggs and flea dirt. And no more dead fleas what a waste of money! I’m so stressed out because it’s disgusting and he’s getting the flea eggs and dirt EVERYWHERE and when we sleep he sneaks on the tables and my baby’s high chair tray and I find them all over those I’m so disgusted. I vacuum and clean everything everyday! What’s a good flea treatment that isn’t frontline and will actually last 30 days and not four… my vet was the one who gave it to us.