Most of the above mentioned flea treatments work fine. It's important to understand how they work, or you'll get the impression they don't.
Very few treatments repel fleas. The vast majority are non-repellant, and work by killing fleas once they jump onto the pet. This means you will still see fleas on the pet: you are seeing those that have recently jumped on from the carpet etc. These fleas will not survive long enough to reproduce.
Where you have an infestation in the house (almost certainly the case where you have an infestation on the pet), you don't WANT to repel them. While it's of course unpleasant for the pet to experience having fleas, a pet treated with a good flea treatment is a walking flea killer.
Pupating fleas in the carpet and furnishings are very difficult to kill. Even the household sprays like Indorex and RIP Fleas won't touch them (though they will kill the other life cycle stages, so are still a mandatory part of clearing a flea infestation).
Adult fleas emerging from a cocoon are, conversely, pretty easy to kill. So we want to encourage them out and onto a passing pet who has been treated with a good product, so they can subsequently die. Leaving them pupating indefinitely in the house will only prolong the infestation.
So, the key points in clearing a flea infestation are:
- Treat all dogs and cats in the household with a decent product. Keep doing it religiously at the recommended interval.
- Treat the house with a good spray like Indorex or RIP Fleas. Do it thoroughly (move furniture, vacuum first, get in every nook and cranny) - it lasts 6-12 months so you shouldn't need to do it regularly, but DO do it well.
- Vacuum daily. This sucks up eggs and larvae, and the vibrations can encourage pupating fleas to emerge from their cocoons and ultimately die.
- Expect to see fleas on the pet for a while.
- Expect complete resolution of the infestation to take weeks-months. Unfortunately it's not a quick process. Which sucks.
Pets who are extremely itchy or making themselves sore can benefit from anti-itch medication while you're getting things under control. The vet will be able to advise on this.
Do note that some oral flea treatments contain nitenpyram (eg Capstar). These are great at killing the fleas that are on the pet at the time you give the dose. But they have no lasting action, so within a couple of days the pet is no longer a walking flea killer. It's important to use a monthly (or three-monthly in the case of ie Bravecto) treatment as well.