Any relationship without effective and efficient communication is going to have problems sooner or Later.
Don’t waste your precious time with someone who keeps complaining of being busy and can't create time for you anymore because there was no such thing at the beginning of your Relationship. Why now? You shouldn’t have to force someone to make a space in their life for you, because if they truly care about you they will gladly create space(s) for you just as they promised.
Being in a relationship with someone who overlooks your worth isn’t loyalty, it’s stupidity. Never beg someone for attention because you'll get tired of asking at all times.
Know your self-worth, and move on if you must.
If he's not returning your calls for no serious reasons, then its a sign that you are an option or have a close substitute.
If you try gaining his attention and he keeps turning you down, pls try someone else....,the land is always green!