How to stop frogs and toads getting into my garden.

 If frogs are coming into your garden they are heading for a breeding pond, and during certain times of the year they will be out and about in numbers. The spring migration to the pond, a mid-summer exodus of young from the pond, and then in Autumn the return to the pond. Mostly moving during damp rainy nights, just like slugs on their way to munch your favourite flowers. Frogs eat slugs!
The damp conditions that attract slugs also attract frogs and frogs eat slugs so I can't see why you should want to stop frogs from coming into your garden at all. However, If the calls are keeping you awake, or if there are frogs getting into your swimming pool, there are two things you can do. 
  1. The main problem seems to be frogs jumping in your pool for a swim and becoming trapped in your swimming pool because they can't get out. You could install a frog ladder in the pool to help them climb out.
  2. If you or your gardener really don't want to share your pond with the gardeners best friend. The only really effective way to stop them is low fencing or a decorative wall installation around the pool that the frogs can't pass. This will also work to keep frogs out of gardens, although given the benefits of having frogs in the garden, I'm not sure why you would want to keep frogs out. Bucket loads of toads or frogs are far better than bucket loads of plant eating slugs and other insects.
Best solution is to learn to live with nature and spend less on chemical slug bait. In the long-term you can't fight nature and win. It's got a way of coming back strong. Swimming with frogs is like swimming with dolphins!!