Welcome to JustAnswer.Where are you seeing the maggots and fruit flies? Inside the house (in what location?), outside, in the soil, etc.?When did this problem first begin?
Depending on whether the maggots/flies are inside your home or outside, there are various ways to get rid of them. The most important thing is to not have anything around that will attract the flies who will then lay their eggs, which turn into maggots. Make sure to cover all garbage receptacles (inside and outside) and not leave any rotting meat or other food garbage in unsealed bags/containers, as this is what attracts the flies. If you have any pets who use the yard to do their business, pick it up immediately, as this will also attract flies.Some of the methods you've already tried, like the insect spray and hot water were good, but you will find more specific and effective methods of getting rid of the flies/maggots here: http://www.maggots.co.za/a-definitive-guide-to-getting-rid-of-maggots/I hope this problem will be resolved for you very soon.