difficult. I presume that you hav eliminated all sources of water in your garden, but if neighbours have ponds or streams, they will still live there...also frogs are creatures of inherited habit and will tend to live where their ancestors did, returning home to spawn, sometimes even when the water has gone. Why are they a nuisance or do you just not like them?
got to say that locally (hampshire UK) we used to have loads more frogs and toads in the garden but they have declined, due I believe to a bacterial infection