It’s very simple. You just need to adjust your daily budget to what you would like to spend each day. If you are running your ads 24/7 and your budget is finished by midday, consider running your ads only during those times when you can actually pick up the phone or at those times when you get the most conversions.
If you are already getting great results, consider increasing your daily budget in order to show your ads during longer periods of time and increase your chances of getting more conversions.