Do they tend to stay on the top floor? Do they prefer warmer or cooler air? Also, do they always avoid lights? (will they prefer to go into a room with no lighting, as opposed to one with lighting)?
You don't say where you are, but in the UK, "getting bats to leave" would be a crime under the Wildlife and Countryside Act (1981) with a maximum sentence of six months prison. Other countries are liable to have similar legislation.
Again, in the UK, I would contact the Bat Conservation Trust at https://www.bats.org.uk/. They will try and help you learn to love your bats (they are wonderful creatures - and they eat mosquitoes), but if they fail at that, they will help you remove them legally.
If you are not in the UK, you will still find their website useful.
We have had bat problems on and off for years, I don’t like killing them because they do eat lots of bugs. For many years we used the ultrasonic pest plug devices with an extension cord to get it closer to the peak they like. 2 years ago we put in led lighting in the arena and use it quite a bit and that also works but the little plug in ultrasonic devices for mice are the best within a day maybe 2 of turning it on they are gone and this is a big area 1 year we needed 2, 1 at each end of the barn as they moved to the other end but we turn these on for a few days 1 or 2x per year if they come back and they go away without hurting them and the cost is a few pennies I think we got 4 of the devices for $10 a few years back. Try it it works.