My boyfriend is the kind of person who will call me back whenever I call him. Although it has been more than a year, it is still very good for me. I think you can talk to the other person about the problems you found and see his reaction. Don't get emotional or anything, just point out your problems objectively.
My boyfriend calls me as soon as he gets off work, except once a day. In fact, college students are just afraid of having nothing to do on vacation. You can find your own hobbies or something, so you won't be so idle. Then make your life more interesting and share your daily life. If you stay at home and nothing new happens every day, then the other person has nothing to say. Of course, you are mutual, and you can also encourage him to pursue his hobbies or something.