How can I get rid of flies?

Try a paper bag blown up and sealed. Hang above your door. The flies think they are wasp nests and stay away.

I'm guessing your flies are from the outdoors and coming in??? The water bags with pennies have never worked for me, either. Here is a solution that does. Buy a 4 oz bottle of essential oil of clove - or the label will read Clove 100% pure. (I like the NOW product). You can find it in health food stores or where essential oils are sold. Pour about 30 oz of water in a spray bottle. Add 2 to 3 tablespoons of oil to the water and replace the top. Shake well. Now, spray the heck out of the outside of your doorways (or windows). Do the patio/steps and nearby walls, too. If there is an area with plants or a planter box, spray that. It is going to smell like cloves. Flies hate that and will move elsewhere. They are usually attracted to decaying material. The clove oil overpowers that odor. It's the best non-toxic solution I've found that works. Hope it helps you, too.

Here are some things you can try.

https://m.wikihow.com/Get-Rid-of-Flies

Flies are frequently repelled by a large concentration of basil, planted near your door entryways, patios, etc.

Here is a post I wrote that might help you https://chascrazycreations.com/irish-spring-soap-and-flies/